CENX

SEC source: 0001144204-18-000370 · tv482510_4.xml · derivative · entry 2

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 74,364.34

Underlying: Common Stock · 93,479 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.exercise_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.expiration_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-18-000370 · tv482510_4.xml · nonDerivative · entry 1

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,069,513

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Represents shares of Common Stock acquired upon conversion of 934.79 shares of Series A Convertible Preferred Stock on December 31, 2017.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-17-051085 · v476357_4.xml · derivative · entry 2

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,299.13

Underlying: Common Stock · 4,715 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.exercise_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.expiration_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-17-051085 · v476357_4.xml · nonDerivative · entry 1

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,976,034

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Represents shares of Common Stock acquired upon conversion of 47.15 shares of Series A Convertible Preferred Stock on September 30, 2017.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-17-048124 · v475137_4.xml · derivative · entry 1

Ryfold Ltd · CIK 0001716574 · 10% owner

Estera Trust (Jersey) Ltd · CIK 0001716591 · 10% owner

Ryfold Trust · CIK 0001716570 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 27,500,000 shares

Expires 2027-09-14

F1 · derivative.exercise_price: On the September 14, 2017, Glencore AG and Ryfold Limited ("Ryfold") entered into a Call Option Agreement (the "Givolon Call Option Agreement") pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold ("Givolon"), for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.

F1 · kind: On the September 14, 2017, Glencore AG and Ryfold Limited ("Ryfold") entered into a Call Option Agreement (the "Givolon Call Option Agreement") pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold ("Givolon"), for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.

F1 · price: On the September 14, 2017, Glencore AG and Ryfold Limited ("Ryfold") entered into a Call Option Agreement (the "Givolon Call Option Agreement") pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold ("Givolon"), for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.

F1 · derivative.exercise_date: On the September 14, 2017, Glencore AG and Ryfold Limited ("Ryfold") entered into a Call Option Agreement (the "Givolon Call Option Agreement") pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold ("Givolon"), for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.

F1 · derivative.expiration_date: On the September 14, 2017, Glencore AG and Ryfold Limited ("Ryfold") entered into a Call Option Agreement (the "Givolon Call Option Agreement") pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold ("Givolon"), for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.

F1 · derivative.underlying_shares: On the September 14, 2017, Glencore AG and Ryfold Limited ("Ryfold") entered into a Call Option Agreement (the "Givolon Call Option Agreement") pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold ("Givolon"), for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.

F2 · ownership.direct: Ryfold's interest in the Call Option is held indirectly by each of Ryfold's parent, The Ryfold Trust, and Estera Trust (Jersey) Limited ("Estera") solely in its capacity as trustee of The Ryfold Trust. Givolon holds directly a number of shares of Common Stock equal to the number of shares reported on Table II, which shares are indirectly owned by each of Ryfold, Ryfold's parent, The Ryfold Trust, and Estera solely in its capacity as trustee of The Ryfold Trust. Estera does not have and disclaims any pecuniary interest in such Common Stock and in the Call Option reported on Table II.

SEC source: 0001144204-17-048122 · v475135_4.xml · derivative · entry 2

Givolon Ltd · CIK 0001716572 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 27,500,000 shares

Expires 2022-12-31

F1 · security: On September 14, 2017 (the "Effective Date"), Givolon Limited ("Givolon"), a wholly-owned subsidiary of Glencore AG at such time, purchased from Glencore AG 27,500,000 shares of common stock ("Common Stock") of Century Aluminum Company (the "Specified Shares") for the aggregate price of $495,845,625, or $18.03075 per share. Subsequently on the Effective Date, Glencore AG sold to Ryfold Limited ("Ryfold") 100% of the equity interests in Givolon for the aggregate purchase price of $100 (the "Givolon Sale").

F7 · security: Under the terms of the Century TRS and the Century Call Option, the Century TRS is scheduled to expire and settle after expiration of the Century Call Option, so that Glencore AG will acquire a number of shares equal to the Specified Shares under the Century TRS even if Glencore AG does not exercise the Century Call Option. In addition, the Century TRS will automatically terminate, with no remaining obligations on the part of either party, upon exercise of the Century Call Option. As a result, under the Century TRS and the Century Call Option, Glencore AG has the right to acquire and Givolon has the obligation to deliver to Glencore AG an aggregate number of shares equal to the Specified Shares. Givolon has granted to Glencore AG the irrevocable right to vote and to direct the voting of the Specified Shares.

F5 · derivative.exercise_price: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.

F6 · derivative.exercise_price: The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F5 · kind: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.

F6 · kind: The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F5 · price: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.

F6 · price: The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F5 · derivative.exercise_date: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.

F6 · derivative.exercise_date: The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F5 · derivative.expiration_date: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.

F6 · derivative.expiration_date: The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F5 · derivative.underlying_shares: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.

F6 · derivative.underlying_shares: The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F8 · ownership.direct: The Specified Shares and Givolon's interests in the Century TRS and the Century Call Option were held indirectly by each of Glencore AG (Givolon's sole shareholder), Glencore AG's parent, Glencore International AG and its parent, Glencore plc, prior to the Givolon Sale, and are held indirectly by each of Ryfold, Ryfold's parent, The Ryfold Trust, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust, following the Givolon Sale.

SEC source: 0001144204-17-048122 · v475135_4.xml · derivative · entry 1

Givolon Ltd · CIK 0001716572 · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 27,500,000 shares

Expires 2022-12-31

F1 · security: On September 14, 2017 (the "Effective Date"), Givolon Limited ("Givolon"), a wholly-owned subsidiary of Glencore AG at such time, purchased from Glencore AG 27,500,000 shares of common stock ("Common Stock") of Century Aluminum Company (the "Specified Shares") for the aggregate price of $495,845,625, or $18.03075 per share. Subsequently on the Effective Date, Glencore AG sold to Ryfold Limited ("Ryfold") 100% of the equity interests in Givolon for the aggregate purchase price of $100 (the "Givolon Sale").

F7 · security: Under the terms of the Century TRS and the Century Call Option, the Century TRS is scheduled to expire and settle after expiration of the Century Call Option, so that Glencore AG will acquire a number of shares equal to the Specified Shares under the Century TRS even if Glencore AG does not exercise the Century Call Option. In addition, the Century TRS will automatically terminate, with no remaining obligations on the part of either party, upon exercise of the Century Call Option. As a result, under the Century TRS and the Century Call Option, Glencore AG has the right to acquire and Givolon has the obligation to deliver to Glencore AG an aggregate number of shares equal to the Specified Shares. Givolon has granted to Glencore AG the irrevocable right to vote and to direct the voting of the Specified Shares.

F2 · derivative.exercise_price: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS").

F3 · derivative.exercise_price: The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F4 · derivative.exercise_price: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · kind: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS").

F3 · kind: The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F4 · kind: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · price: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS").

F3 · price: The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F4 · price: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · derivative.exercise_date: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS").

F3 · derivative.exercise_date: The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F4 · derivative.exercise_date: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · derivative.expiration_date: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS").

F3 · derivative.expiration_date: The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F4 · derivative.expiration_date: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · derivative.underlying_shares: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS").

F3 · derivative.underlying_shares: The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F4 · derivative.underlying_shares: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F8 · ownership.direct: The Specified Shares and Givolon's interests in the Century TRS and the Century Call Option were held indirectly by each of Glencore AG (Givolon's sole shareholder), Glencore AG's parent, Glencore International AG and its parent, Glencore plc, prior to the Givolon Sale, and are held indirectly by each of Ryfold, Ryfold's parent, The Ryfold Trust, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust, following the Givolon Sale.

SEC source: 0001144204-17-048110 · v475138_form4.xml · derivative · entry 7

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 4,400,000 shares

Expires 2021-03-21

F8 · derivative.exercise_price: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F11 · derivative.exercise_price: Pursuant to the Swap Agreement, on March 11, 2011, Glencore International received economic exposure pursuant to a Swap (the "Second Swap") entered into between Glencore International and Citi with an initial expiration date of March 11, 2013 (subsequently extended twice to September 17, 2017).

F12 · derivative.exercise_price: Upon expiration of the Second Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,400,000 shares of common stock referenced by the Second Swap (the "Second Subject Shares") from the $16.6582 per share volume weighted average price calculated during the initial averaging period for the Second Swap (which ended on March 11, 2011) to the volume weighted average price of the Second Subject Shares during the final valuation period preceding the expiration of the term of the Second Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F13 · derivative.exercise_price: Under the terms of the Swap Agreement, generally, Glencore International will be obligated to post cash collateral to Citi and pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the Company on the First Subject Shares and the Second Subject Shares.

F8 · kind: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F11 · kind: Pursuant to the Swap Agreement, on March 11, 2011, Glencore International received economic exposure pursuant to a Swap (the "Second Swap") entered into between Glencore International and Citi with an initial expiration date of March 11, 2013 (subsequently extended twice to September 17, 2017).

F12 · kind: Upon expiration of the Second Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,400,000 shares of common stock referenced by the Second Swap (the "Second Subject Shares") from the $16.6582 per share volume weighted average price calculated during the initial averaging period for the Second Swap (which ended on March 11, 2011) to the volume weighted average price of the Second Subject Shares during the final valuation period preceding the expiration of the term of the Second Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F13 · kind: Under the terms of the Swap Agreement, generally, Glencore International will be obligated to post cash collateral to Citi and pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the Company on the First Subject Shares and the Second Subject Shares.

F11 · shares: Pursuant to the Swap Agreement, on March 11, 2011, Glencore International received economic exposure pursuant to a Swap (the "Second Swap") entered into between Glencore International and Citi with an initial expiration date of March 11, 2013 (subsequently extended twice to September 17, 2017).

F12 · shares: Upon expiration of the Second Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,400,000 shares of common stock referenced by the Second Swap (the "Second Subject Shares") from the $16.6582 per share volume weighted average price calculated during the initial averaging period for the Second Swap (which ended on March 11, 2011) to the volume weighted average price of the Second Subject Shares during the final valuation period preceding the expiration of the term of the Second Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F13 · shares: Under the terms of the Swap Agreement, generally, Glencore International will be obligated to post cash collateral to Citi and pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the Company on the First Subject Shares and the Second Subject Shares.

F8 · price: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F11 · price: Pursuant to the Swap Agreement, on March 11, 2011, Glencore International received economic exposure pursuant to a Swap (the "Second Swap") entered into between Glencore International and Citi with an initial expiration date of March 11, 2013 (subsequently extended twice to September 17, 2017).

F12 · price: Upon expiration of the Second Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,400,000 shares of common stock referenced by the Second Swap (the "Second Subject Shares") from the $16.6582 per share volume weighted average price calculated during the initial averaging period for the Second Swap (which ended on March 11, 2011) to the volume weighted average price of the Second Subject Shares during the final valuation period preceding the expiration of the term of the Second Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F13 · price: Under the terms of the Swap Agreement, generally, Glencore International will be obligated to post cash collateral to Citi and pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the Company on the First Subject Shares and the Second Subject Shares.

F14 · derivative.exercise_date: On September 14, 2017 the expiration date of each of the First Swap and the Second Swap was extended to April 17, 2018 and thereafter will automatically extend for successive seven month periods, with a final expiration date of March 17, 2021, subject to termination at Glencore Canada's election on any automatic extension date.

F14 · derivative.expiration_date: On September 14, 2017 the expiration date of each of the First Swap and the Second Swap was extended to April 17, 2018 and thereafter will automatically extend for successive seven month periods, with a final expiration date of March 17, 2021, subject to termination at Glencore Canada's election on any automatic extension date.

F8 · derivative.underlying_shares: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F11 · derivative.underlying_shares: Pursuant to the Swap Agreement, on March 11, 2011, Glencore International received economic exposure pursuant to a Swap (the "Second Swap") entered into between Glencore International and Citi with an initial expiration date of March 11, 2013 (subsequently extended twice to September 17, 2017).

F12 · derivative.underlying_shares: Upon expiration of the Second Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,400,000 shares of common stock referenced by the Second Swap (the "Second Subject Shares") from the $16.6582 per share volume weighted average price calculated during the initial averaging period for the Second Swap (which ended on March 11, 2011) to the volume weighted average price of the Second Subject Shares during the final valuation period preceding the expiration of the term of the Second Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F13 · derivative.underlying_shares: Under the terms of the Swap Agreement, generally, Glencore International will be obligated to post cash collateral to Citi and pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the Company on the First Subject Shares and the Second Subject Shares.

F8 · balance_after: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F11 · balance_after: Pursuant to the Swap Agreement, on March 11, 2011, Glencore International received economic exposure pursuant to a Swap (the "Second Swap") entered into between Glencore International and Citi with an initial expiration date of March 11, 2013 (subsequently extended twice to September 17, 2017).

F12 · balance_after: Upon expiration of the Second Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,400,000 shares of common stock referenced by the Second Swap (the "Second Subject Shares") from the $16.6582 per share volume weighted average price calculated during the initial averaging period for the Second Swap (which ended on March 11, 2011) to the volume weighted average price of the Second Subject Shares during the final valuation period preceding the expiration of the term of the Second Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F13 · balance_after: Under the terms of the Swap Agreement, generally, Glencore International will be obligated to post cash collateral to Citi and pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the Company on the First Subject Shares and the Second Subject Shares.

F8 · ownership.direct: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F15 · ownership.direct: The cash settled total return swaps reported in Table II are held directly by Glencore Canada (following Glencore International's transfer to it of the Citi Swap Agreement and all agreements and transactions thereunder on September 14, 2017), and may be deemed to be beneficially owned indirectly by Glencore plc. The cash settled total return swaps do not give Glencore Canada or the reporting persons direct or indirect voting, investment or dispositive control over any securities of the issuer, and accordingly, the reporting persons disclaim any beneficial ownership in the First Subject Shares and the Second Subject Shares. Glencore Canada does not beneficially own (within the meaning of Rule13d-3) any equity securities of the Company of a class registered pursuant to Section 12 of the Securities Act of 1933, as amended.

SEC source: 0001144204-17-048110 · v475138_form4.xml · derivative · entry 6

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 4,729,302 shares

Expires 2021-03-21

F8 · derivative.exercise_price: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F9 · derivative.exercise_price: Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the "First Swap") entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended twice to September 17, 2017).

F10 · derivative.exercise_price: Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the "First Subject Shares") from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F8 · kind: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F9 · kind: Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the "First Swap") entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended twice to September 17, 2017).

F10 · kind: Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the "First Subject Shares") from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F9 · shares: Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the "First Swap") entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended twice to September 17, 2017).

F10 · shares: Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the "First Subject Shares") from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F8 · price: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F9 · price: Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the "First Swap") entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended twice to September 17, 2017).

F10 · price: Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the "First Subject Shares") from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F14 · derivative.exercise_date: On September 14, 2017 the expiration date of each of the First Swap and the Second Swap was extended to April 17, 2018 and thereafter will automatically extend for successive seven month periods, with a final expiration date of March 17, 2021, subject to termination at Glencore Canada's election on any automatic extension date.

F14 · derivative.expiration_date: On September 14, 2017 the expiration date of each of the First Swap and the Second Swap was extended to April 17, 2018 and thereafter will automatically extend for successive seven month periods, with a final expiration date of March 17, 2021, subject to termination at Glencore Canada's election on any automatic extension date.

F8 · derivative.underlying_shares: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F9 · derivative.underlying_shares: Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the "First Swap") entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended twice to September 17, 2017).

F10 · derivative.underlying_shares: Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the "First Subject Shares") from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F8 · balance_after: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F9 · balance_after: Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the "First Swap") entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended twice to September 17, 2017).

F10 · balance_after: Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the "First Subject Shares") from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.

F8 · ownership.direct: On July 2, 2010, Glencore International entered into a Master Terms and Conditions for Swap Transactions agreement (the "Swap Agreement") with Citigroup Global Markets Inc. ("Citi"), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the "Swaps"). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Citi Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly owned subsidiary of Glencore plc ("Glencore Canada").

F15 · ownership.direct: The cash settled total return swaps reported in Table II are held directly by Glencore Canada (following Glencore International's transfer to it of the Citi Swap Agreement and all agreements and transactions thereunder on September 14, 2017), and may be deemed to be beneficially owned indirectly by Glencore plc. The cash settled total return swaps do not give Glencore Canada or the reporting persons direct or indirect voting, investment or dispositive control over any securities of the issuer, and accordingly, the reporting persons disclaim any beneficial ownership in the First Subject Shares and the Second Subject Shares. Glencore Canada does not beneficially own (within the meaning of Rule13d-3) any equity securities of the Company of a class registered pursuant to Section 12 of the Securities Act of 1933, as amended.

SEC source: 0001144204-17-048110 · v475138_form4.xml · derivative · entry 5

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 27,500,000 shares

Expires 2027-09-14

F6 · derivative.exercise_price: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F6 · kind: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F6 · price: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F6 · derivative.exercise_date: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F6 · derivative.expiration_date: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F6 · derivative.underlying_shares: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F6 · ownership.direct: On the Effective Date, Glencore AG and Ryfold entered into a Call Option Agreement pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon for an aggregate exercise price of $100 (the "Givolon Call Option"). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option. Givolon holds directly a number of shares equal to the Specified Shares, which shares are indirectly owned by each of Ryfold, The Ryfold Trust, which is the parent of Ryfold, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust.

F7 · ownership.direct: The shares of Common Stock reported on Table I and the Total Return Swap and the Call Options reported on Table II are held directly by Glencore AG, and indirectly by each of Glencore AG's parent, Glencore International and its parent, Glencore plc.

SEC source: 0001144204-17-048110 · v475138_form4.xml · derivative · entry 4

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 27,500,000 shares

Expires 2022-12-31

F5 · security: Under the terms of the Century TRS and the Century Call Option, the Century TRS is scheduled to expire and settle after expiration of the Century Call Option, so that Glencore AG will acquire a number of shares equal to the Specified Shares under the Century TRS even if Glencore AG does not exercise the Century Call Option. In addition, the Century TRS will automatically terminate, with no remaining obligations on the part of either party, upon exercise of the Century Call Option. As a result, under the Century TRS and the Century Call Option, Glencore AG has the right to acquire and Givolon has the obligation to deliver to Glencore AG an aggregate number of shares equal to the Specified Shares. Givolon has granted to Glencore AG the irrevocable right to vote and to direct the voting of the Specified Shares.

F4 · derivative.exercise_price: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option. The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F4 · kind: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option. The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F4 · price: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option. The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F4 · derivative.exercise_date: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option. The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F4 · derivative.expiration_date: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option. The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F4 · derivative.underlying_shares: On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the "Century Call Option"). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option. The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.

F7 · ownership.direct: The shares of Common Stock reported on Table I and the Total Return Swap and the Call Options reported on Table II are held directly by Glencore AG, and indirectly by each of Glencore AG's parent, Glencore International and its parent, Glencore plc.

SEC source: 0001144204-17-048110 · v475138_form4.xml · derivative · entry 3

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 1

Underlying: Common Stock · 27,500,000 shares

Expires 2022-12-31

F5 · security: Under the terms of the Century TRS and the Century Call Option, the Century TRS is scheduled to expire and settle after expiration of the Century Call Option, so that Glencore AG will acquire a number of shares equal to the Specified Shares under the Century TRS even if Glencore AG does not exercise the Century Call Option. In addition, the Century TRS will automatically terminate, with no remaining obligations on the part of either party, upon exercise of the Century Call Option. As a result, under the Century TRS and the Century Call Option, Glencore AG has the right to acquire and Givolon has the obligation to deliver to Glencore AG an aggregate number of shares equal to the Specified Shares. Givolon has granted to Glencore AG the irrevocable right to vote and to direct the voting of the Specified Shares.

F2 · derivative.exercise_price: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS"). The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F3 · derivative.exercise_price: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · kind: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS"). The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F3 · kind: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · price: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS"). The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F3 · price: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · derivative.exercise_date: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS"). The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F3 · derivative.exercise_date: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · derivative.expiration_date: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS"). The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F3 · derivative.expiration_date: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F2 · derivative.underlying_shares: On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the "Master Agreement") and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the "Century TRS"). The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the "Expiration Date").

F3 · derivative.underlying_shares: Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.

F7 · ownership.direct: The shares of Common Stock reported on Table I and the Total Return Swap and the Call Options reported on Table II are held directly by Glencore AG, and indirectly by each of Glencore AG's parent, Glencore International and its parent, Glencore plc.

SEC source: 0001144204-17-048110 · v475138_form4.xml · nonDerivative · entry 1

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 0

F1 · kind: The reported securities (the "Specified Shares") are held by Givolon Limited ("Givolon") and prior to the transaction described in the following sentence, were held indirectly by each of Glencore AG, Glencore AG's parent, Glencore International AG ("Glencore International") and its parent, Glencore plc. On September 14, 2017 (the "Effective Date"), Glencore AG sold to Ryfold Limited ("Ryfold") 100% of the equity interests in Givolon (of which Glencore AG was the sole shareholder) for the aggregate purchase price of $100 (the "Givolon Sale"). Prior to the Givolon Sale on the Effective Date, Givolon, a wholly-owned subsidiary of Glencore AG at such time, purchased from Glencore AG the Specified Shares for the aggregate price of $495,845,625, or $18.03075 per share (the "Specified Shares Sale"). Immediately following the Specified Shares Sale, Glencore AG continued to hold directly 9,971,319 shares of Common Stock as set forth on row 2 in Table I.

F1 · price: The reported securities (the "Specified Shares") are held by Givolon Limited ("Givolon") and prior to the transaction described in the following sentence, were held indirectly by each of Glencore AG, Glencore AG's parent, Glencore International AG ("Glencore International") and its parent, Glencore plc. On September 14, 2017 (the "Effective Date"), Glencore AG sold to Ryfold Limited ("Ryfold") 100% of the equity interests in Givolon (of which Glencore AG was the sole shareholder) for the aggregate purchase price of $100 (the "Givolon Sale"). Prior to the Givolon Sale on the Effective Date, Givolon, a wholly-owned subsidiary of Glencore AG at such time, purchased from Glencore AG the Specified Shares for the aggregate price of $495,845,625, or $18.03075 per share (the "Specified Shares Sale"). Immediately following the Specified Shares Sale, Glencore AG continued to hold directly 9,971,319 shares of Common Stock as set forth on row 2 in Table I.

F1 · ownership.nature: The reported securities (the "Specified Shares") are held by Givolon Limited ("Givolon") and prior to the transaction described in the following sentence, were held indirectly by each of Glencore AG, Glencore AG's parent, Glencore International AG ("Glencore International") and its parent, Glencore plc. On September 14, 2017 (the "Effective Date"), Glencore AG sold to Ryfold Limited ("Ryfold") 100% of the equity interests in Givolon (of which Glencore AG was the sole shareholder) for the aggregate purchase price of $100 (the "Givolon Sale"). Prior to the Givolon Sale on the Effective Date, Givolon, a wholly-owned subsidiary of Glencore AG at such time, purchased from Glencore AG the Specified Shares for the aggregate price of $495,845,625, or $18.03075 per share (the "Specified Shares Sale"). Immediately following the Specified Shares Sale, Glencore AG continued to hold directly 9,971,319 shares of Common Stock as set forth on row 2 in Table I.

SEC source: 0001144204-17-035520 · v470297_4.xml · derivative · entry 2

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,346.28

Underlying: Common Stock · 23,109 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.exercise_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.expiration_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-17-035520 · v470297_4.xml · nonDerivative · entry 1

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,471,319

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Represents shares of Common Stock acquired upon conversion of 231.09 shares of Series A Convertible Preferred Stock on June 30, 2017.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0000949157-17-000055 · wf-form4_149816247698136.xml · nonDerivative · entry 1

Wilkinson Terence · CIK 0001522873 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 61,980

F1 · shares: Annual grant of service based performance shares units made to directors on June 20, 2017, pursuant to Rule 16b-3(d) plan, all of which vest immediately.

F2 · shares: Settlement of the performance shares has been deferred until the termination of the reporting person's service as a director of the Company.

F3 · balance_after: Includes deferred performance share units to the Reporting Person in connection with previous annual grants of Performance Shares made to the Reporting Person pursuant to a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000054 · wf-form4_149816242490965.xml · nonDerivative · entry 1

GLASSER ERROL · CIK 0001203889 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 35,100

F1 · shares: Annual grant of service based performance shares units made to directors on June 20, 2017, (the "Grant Date") pursuant to Rule 16b-3(d) plan, all of which vests on the one year anniversary of the Grant Date or upon the earlier occurrence of certain other events.

F2 · shares: Settlement of the performance shares has been deferred until the termination of the reporting person's service as a director of the Company.

F3 · balance_after: Includes deferred performance share units to the Reporting Person in connection with previous annual grants of Performance Shares made to the Reporting Person pursuant to a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000053 · wf-form4_149816233064147.xml · nonDerivative · entry 1

Berntzen Jarl · CIK 0001355035 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 97,908

F1 · shares: Includes (i) 6,228 performance shares granted to the reporting person on June 20, 2017 pursuant to a Rule 16b-3(d) plan representing the annual grant of service based performance shares made to directors which vest on the one year anniversary of the grant date or earlier upon the occurrence of certain other events and (ii) 3,114 performance shares granted to the reporting person on June 20, 2017 pursuant to a Rule 16b-3(d) plan representing the reporting person's annual retainer which will vest in four equal quarterly installments.

F2 · shares: Settlement of the performance shares has been deferred until the termination of the reporting person's service as a director of the Company.

F3 · balance_after: Includes deferred performance share units to the Reporting Person in connection with previous annual grants of Performance Shares made to the Reporting Person pursuant to a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000048 · wf-form4_149582887603682.xml · derivative · entry 3

BLESS MICHAEL A · CIK 0001204903 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 27,618 shares

Expires 2019-05-04

SEC source: 0000949157-17-000048 · wf-form4_149582887603682.xml · nonDerivative · entry 2

BLESS MICHAEL A · CIK 0001204903 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 347,334

F2 · price: This transaction was executed in multiple trades at prices ranging from $14.80 to $14.99. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

F1 · balance_after: Includes unvested time vesting performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Long-Term Incentive Plans under Rule 16b-3(d).

SEC source: 0000949157-17-000048 · wf-form4_149582887603682.xml · nonDerivative · entry 1

BLESS MICHAEL A · CIK 0001204903 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 374,952

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · balance_after: Includes unvested time vesting performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Long-Term Incentive Plans under Rule 16b-3(d).

SEC source: 0000949157-17-000042 · wf-form4_149366979611572.xml · nonDerivative · entry 1

BLESS MICHAEL A · CIK 0001204903 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 347,334

F1 · balance_after: Includes unvested performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Performance Share Programs under a Rule 16b-3(d) plan.

SEC source: 0001144204-17-018424 · v463341_4.xml · derivative · entry 2

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,577.37

Underlying: Common Stock · 4,795 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.exercise_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.expiration_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-17-018424 · v463341_4.xml · nonDerivative · entry 1

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,448,210

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Represents shares of Common Stock acquired upon conversion of 47.95 shares of Series A Convertible Preferred Stock on March 31, 2017.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0000949157-17-000023 · wf-form4_148840305664768.xml · nonDerivative · entry 2

Lair Michelle · CIK 0001365895 · Sr. VP Finance & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 47,483

SEC source: 0000949157-17-000023 · wf-form4_148840305664768.xml · nonDerivative · entry 1

Lair Michelle · CIK 0001365895 · Sr. VP Finance & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,355

F1 · shares: This transaction was executed in multiple trades at prices ranging from $13.62 to $13.97. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.

SEC source: 0000949157-17-000010 · wf-form4_148356080021523.xml · nonDerivative · entry 1

Heyroth Stephen K. · CIK 0001638425 · Chief Accounting Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,435

F1 · shares: Represents time vesting performance share units granted to the Reporting Person in connection with the Issuer's 2017-2019 Long-Term Incentive Plan under Rule 16b-3(d), all of which will vest in the ordinary course on the last day of the Plan Period, December 31, 2019.

F2 · balance_after: Includes unvested performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Performance Share Programs under a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000009 · wf-form4_148356069978160.xml · nonDerivative · entry 2

Hoerner John E. · CIK 0001529248 · EVP - N. American Operations

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 103,296

F3 · shares: Represents time vesting performance share units granted to the Reporting Person in connection with the Issuer's 2017-2019 Long-Term Incentive Plan under Rule 16b-3(d), all of which will vest in the ordinary course on the last day of the Plan Period, December 31, 2019.

F4 · balance_after: Includes unvested performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Performance Share Programs under a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000008 · wf-form4_148356053112567.xml · nonDerivative · entry 2

Lair Michelle · CIK 0001365895 · Sr. VP Finance & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 54,480

F3 · shares: Represents time vesting performance share units granted to the Reporting Person in connection with the Issuer's 2017-2019 Long-Term Incentive Plan under Rule 16b-3(d), all of which will vest in the ordinary course on the last day of the Plan Period, December 31, 2019.

F4 · balance_after: Includes unvested performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Performance Share Programs under a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000007 · wf-form4_148356039126025.xml · nonDerivative · entry 2

Gary Jesse E · CIK 0001568817 · EVP, Gen. Counsel & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 95,987

F3 · shares: Represents time vesting performance share units granted to the Reporting Person in connection with the Issuer's 2017-2019 Long-Term Incentive Plan under Rule 16b-3(d), all of which will vest in the ordinary course on the last day of the Plan Period, December 31, 2019.

F4 · balance_after: Includes unvested performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Performance Share Programs under a Rule 16b-3(d) plan.

SEC source: 0000949157-17-000006 · wf-form4_148356015993817.xml · nonDerivative · entry 2

BLESS MICHAEL A · CIK 0001204903 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 355,334

F3 · shares: Represents time vesting performance share units granted to the Reporting Person in connection with the Issuer's 2017-2019 Long-Term Incentive Plan under Rule 16b-3(d), all of which will vest in the ordinary course on the last day of the Plan Period, December 31, 2019.

F4 · balance_after: Includes unvested performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017, 2016-2018 and 2017-2019 Performance Share Programs under a Rule 16b-3(d) plan.

SEC source: 0001144204-17-000080 · v456067_4.xml · derivative · entry 2

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 75,625.32

Underlying: Common Stock · 75,253 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.exercise_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F2 · derivative.expiration_date: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0001144204-17-000080 · v456067_4.xml · nonDerivative · entry 1

Glencore AG · CIK 0001449539 · 10% owner

GLENCORE INTERNATIONAL AG · CIK 0001032383 · 10% owner

Glencore plc · CIK 0001521365 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 37,443,415

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: Represents shares of Common Stock acquired upon conversion of 752.53 shares of Series A Convertible Preferred Stock on December 31, 2016.

F2 · price: Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.

F3 · ownership.direct: The shares of Common Stock reported in Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and indirectly by Glencore International AG and its parent, Glencore plc.

SEC source: 0000949157-17-000009 · wf-form4_148356069978160.xml · nonDerivative · entry 1

Hoerner John E. · CIK 0001529248 · EVP - N. American Operations

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 84,545

F1 · shares: Reports shares withheld by the Issuer to satisfy tax obligations in connection with the vesting of performance share units granted to the Reporting Person.

F2 · balance_after: Includes unvested time vesting performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017 and 2016-2018 Long-Term Incentive Plans under Rule 16b-3(d).

SEC source: 0000949157-17-000008 · wf-form4_148356053112567.xml · nonDerivative · entry 1

Lair Michelle · CIK 0001365895 · Sr. VP Finance & Treasurer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 47,745

F1 · shares: Reports shares withheld by the Issuer to satisfy tax obligations in connection with the vesting of performance share units granted to the Reporting Person.

F2 · balance_after: Includes unvested time vesting performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017 and 2016-2018 Long-Term Incentive Plans under Rule 16b-3(d).

SEC source: 0000949157-17-000007 · wf-form4_148356039126025.xml · nonDerivative · entry 1

Gary Jesse E · CIK 0001568817 · EVP, Gen. Counsel & Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 66,890

F1 · shares: Reports shares withheld by the Issuer to satisfy tax obligations in connection with the vesting of performance share units granted to the Reporting Person.

F2 · balance_after: Includes unvested time vesting performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017 and 2016-2018 Long-Term Incentive Plans under Rule 16b-3(d).

SEC source: 0000949157-17-000006 · wf-form4_148356015993817.xml · nonDerivative · entry 1

BLESS MICHAEL A · CIK 0001204903 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 298,025

F1 · shares: Reports shares withheld by the Issuer to satisfy tax obligations in connection with the vesting of performance share units granted to the Reporting Person.

F2 · balance_after: Includes unvested time vesting performance share units granted to the Reporting Person pursuant to Issuer's 2015-2017 and 2016-2018 Long-Term Incentive Plans under Rule 16b-3(d).