MPLX Holdings Inc.

SEC source: 0001209191-18-007307 · doc4.xml · nonDerivative · entry 1

Marathon Petroleum Corp · CIK 0001510295 · Director · 10% owner

MPC Investment LLC · CIK 0001560713 · Director · 10% owner

MPLX GP LLC · CIK 0001551999 · Director · 10% owner

MPLX Logistics Holdings LLC · CIK 0001551994 · Director · 10% owner

MPLX Holdings Inc. · CIK 0001683291 · Director

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 504,701,934

F1 · shares: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment LLC ("MPCI"), MPLX GP LLC (the "GP"), MPLX Logistics Holdings LLC ("Logistics") and MPLX Holdings Inc. ("Holdings"). MPCI, a direct wholly owned subsidiary of MPC, owns all of the membership interests in both the GP and Logistics and all the shares of stock of Holdings. Accordingly, the GP, Logistics and Holdings are all indirect wholly owned subsidiaries of MPC.

F2 · shares: Pursuant to the Membership Interests Contribution Agreement dated November 13, 2017 among the Issuer, Logistics, Holdings, the GP and MPCI, on 2/1/2018, MPCI contributed: the membership interests in MPLX Refining Logistics LLC, which owns all of the membership interests in each of Canton Refining Logistics LLC, Catlettsburg Refining Logistics LLC, Detroit Refining Logistics LLC, Galveston Bay Refining Logistics LLC, Garyville Refining Logistics LLC and Robinson Refining Logistics LLC; and all of the membership interests in MPLX Fuels Distribution LLC, to the Issuer for $4.1 billion in cash consideration and equity consideration, consisting of (i) 85,610,278 common units issued to the GP, (ii) 18,176,666 common units issued to Logistics, (iii) 7,824,167 common units issued to Holdings and (iv) 2,277,778 general partner units issued to the GP.

F3 · shares: Pursuant to the Partnership Interests Restructuring Agreement dated December 15, 2017, between the Issuer and the GP, on 2/1/2018, the GP converted its 10,586,691 general partner units, representing its 2% general partner interest in the Issuer, into a non-economic general partner interest in the Issuer and the GP's general partner units and incentive distribution rights were cancelled and redeemed, in exchange for 275,000,000 newly issued common units issued to the GP.

F2 · price: Pursuant to the Membership Interests Contribution Agreement dated November 13, 2017 among the Issuer, Logistics, Holdings, the GP and MPCI, on 2/1/2018, MPCI contributed: the membership interests in MPLX Refining Logistics LLC, which owns all of the membership interests in each of Canton Refining Logistics LLC, Catlettsburg Refining Logistics LLC, Detroit Refining Logistics LLC, Galveston Bay Refining Logistics LLC, Garyville Refining Logistics LLC and Robinson Refining Logistics LLC; and all of the membership interests in MPLX Fuels Distribution LLC, to the Issuer for $4.1 billion in cash consideration and equity consideration, consisting of (i) 85,610,278 common units issued to the GP, (ii) 18,176,666 common units issued to Logistics, (iii) 7,824,167 common units issued to Holdings and (iv) 2,277,778 general partner units issued to the GP.

F3 · price: Pursuant to the Partnership Interests Restructuring Agreement dated December 15, 2017, between the Issuer and the GP, on 2/1/2018, the GP converted its 10,586,691 general partner units, representing its 2% general partner interest in the Issuer, into a non-economic general partner interest in the Issuer and the GP's general partner units and incentive distribution rights were cancelled and redeemed, in exchange for 275,000,000 newly issued common units issued to the GP.

F1 · ownership.nature: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment LLC ("MPCI"), MPLX GP LLC (the "GP"), MPLX Logistics Holdings LLC ("Logistics") and MPLX Holdings Inc. ("Holdings"). MPCI, a direct wholly owned subsidiary of MPC, owns all of the membership interests in both the GP and Logistics and all the shares of stock of Holdings. Accordingly, the GP, Logistics and Holdings are all indirect wholly owned subsidiaries of MPC.

F2 · ownership.nature: Pursuant to the Membership Interests Contribution Agreement dated November 13, 2017 among the Issuer, Logistics, Holdings, the GP and MPCI, on 2/1/2018, MPCI contributed: the membership interests in MPLX Refining Logistics LLC, which owns all of the membership interests in each of Canton Refining Logistics LLC, Catlettsburg Refining Logistics LLC, Detroit Refining Logistics LLC, Galveston Bay Refining Logistics LLC, Garyville Refining Logistics LLC and Robinson Refining Logistics LLC; and all of the membership interests in MPLX Fuels Distribution LLC, to the Issuer for $4.1 billion in cash consideration and equity consideration, consisting of (i) 85,610,278 common units issued to the GP, (ii) 18,176,666 common units issued to Logistics, (iii) 7,824,167 common units issued to Holdings and (iv) 2,277,778 general partner units issued to the GP.

F3 · ownership.nature: Pursuant to the Partnership Interests Restructuring Agreement dated December 15, 2017, between the Issuer and the GP, on 2/1/2018, the GP converted its 10,586,691 general partner units, representing its 2% general partner interest in the Issuer, into a non-economic general partner interest in the Issuer and the GP's general partner units and incentive distribution rights were cancelled and redeemed, in exchange for 275,000,000 newly issued common units issued to the GP.

SEC source: 0001209191-17-051191 · doc4.xml · nonDerivative · entry 1

Marathon Petroleum Corp · CIK 0001510295 · Director · 10% owner

MPC Investment LLC · CIK 0001560713 · Director · 10% owner

MPLX GP LLC · CIK 0001551999 · Director

MPLX Logistics Holdings LLC · CIK 0001551994 · Director · 10% owner

MPLX Holdings Inc. · CIK 0001683291 · Director

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 118,090,823

F1 · shares: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment LLC ("MPCI"), MPLX GP LLC (the "GP"), MPLX Logistics Holdings LLC ("Logistics") and MPLX Holdings Inc. ("Holdings"). MPCI, a direct wholly-owned subsidiary of MPC, owns all of the membership interests in both the GP and Logistics and all of the shares of stock of Holdings. Accordingly, the GP, Logistics and Holdings are all indirect wholly-owned subsidiaries of MPC.

F2 · shares: Pursuant to the Membership Interests and Shares Contributions Agreement among the Issuer, Logistics, Holdings, the GP and MPCI, on 9/1/2017, MPCI agreed to contribute: the membership interests of Lincoln Pipeline LLC, which holds a 35% interest in Illinois Extension Pipeline Company, L.L.C.; the membership interests of MPL Louisiana Holdings LLC, which holds a 40.7% interest in LOOP LLC; a 58.52% interest in LOCAP LLC; and a 24.51% interest in Explorer Pipeline Company, to the Issuer for $420 million in cash and equity consideration valued at $630 million, consisting of: (i) 13,719,017 common units issued to the GP, (ii) 3,350,893 common units issued to Logistics, (iii) 1,441,224 common units issued to Holdings and (iv) 377,778 general partner units issued to the GP. The units issued were calculated by dividing $630 million by $33.3529, the simple average of the 10 day trading volume weighted average price of a common unit for the 10 trading days ending 8/31/2017.

F3 · shares: The GP directly owns 8,306,911 general partner units, representing its 2% general partner interest in the Issuer. MPCI owns all of the membership interest in the GP and MPC owns all of the membership interest in MPCI. Accordingly, MPC and MPCI both may be deemed to indirectly beneficially own the securities of the Issuer directly held by the GP, but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F2 · price: Pursuant to the Membership Interests and Shares Contributions Agreement among the Issuer, Logistics, Holdings, the GP and MPCI, on 9/1/2017, MPCI agreed to contribute: the membership interests of Lincoln Pipeline LLC, which holds a 35% interest in Illinois Extension Pipeline Company, L.L.C.; the membership interests of MPL Louisiana Holdings LLC, which holds a 40.7% interest in LOOP LLC; a 58.52% interest in LOCAP LLC; and a 24.51% interest in Explorer Pipeline Company, to the Issuer for $420 million in cash and equity consideration valued at $630 million, consisting of: (i) 13,719,017 common units issued to the GP, (ii) 3,350,893 common units issued to Logistics, (iii) 1,441,224 common units issued to Holdings and (iv) 377,778 general partner units issued to the GP. The units issued were calculated by dividing $630 million by $33.3529, the simple average of the 10 day trading volume weighted average price of a common unit for the 10 trading days ending 8/31/2017.

F1 · ownership.nature: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment LLC ("MPCI"), MPLX GP LLC (the "GP"), MPLX Logistics Holdings LLC ("Logistics") and MPLX Holdings Inc. ("Holdings"). MPCI, a direct wholly-owned subsidiary of MPC, owns all of the membership interests in both the GP and Logistics and all of the shares of stock of Holdings. Accordingly, the GP, Logistics and Holdings are all indirect wholly-owned subsidiaries of MPC.

F2 · ownership.nature: Pursuant to the Membership Interests and Shares Contributions Agreement among the Issuer, Logistics, Holdings, the GP and MPCI, on 9/1/2017, MPCI agreed to contribute: the membership interests of Lincoln Pipeline LLC, which holds a 35% interest in Illinois Extension Pipeline Company, L.L.C.; the membership interests of MPL Louisiana Holdings LLC, which holds a 40.7% interest in LOOP LLC; a 58.52% interest in LOCAP LLC; and a 24.51% interest in Explorer Pipeline Company, to the Issuer for $420 million in cash and equity consideration valued at $630 million, consisting of: (i) 13,719,017 common units issued to the GP, (ii) 3,350,893 common units issued to Logistics, (iii) 1,441,224 common units issued to Holdings and (iv) 377,778 general partner units issued to the GP. The units issued were calculated by dividing $630 million by $33.3529, the simple average of the 10 day trading volume weighted average price of a common unit for the 10 trading days ending 8/31/2017.

F3 · ownership.nature: The GP directly owns 8,306,911 general partner units, representing its 2% general partner interest in the Issuer. MPCI owns all of the membership interest in the GP and MPC owns all of the membership interest in MPCI. Accordingly, MPC and MPCI both may be deemed to indirectly beneficially own the securities of the Issuer directly held by the GP, but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-17-018011 · doc4.xml · nonDerivative · entry 1

Marathon Petroleum Corp · CIK 0001510295 · Director · 10% owner

MPC Investment LLC · CIK 0001560713 · Director · 10% owner

MPLX GP LLC · CIK 0001551999 · Director

MPLX Logistics Holdings LLC · CIK 0001551994 · Director · 10% owner

MPLX Holdings Inc. · CIK 0001683291 · Director

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 99,579,689

F1 · shares: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment LLC ("MPC Investment"), MPLX GP LLC (the "General Partner"), MPLX Logistics Holdings LLC ("MPLX Logistics") and MPLX Holdings Inc. ("MPLX Holdings"). MPC Investment, a direct wholly-owned subsidiary of MPC, owns all of the membership interests in both the General Partner and MPLX Logistics and all of the shares of stock of MPLX Holdings. Accordingly, the General Partner, MPLX Logistics and MPLX Holdings are indirect wholly-owned subsidiaries of MPC.

F2 · shares: The General Partner directly owns 7,636,916 general partner units, representing its 2% general partner interest in the Issuer. MPC Investment owns all of the membership interest in the General Partner and MPC owns all of the membership interest in MPC Investment. Accordingly, MPC and MPC Investment both may be deemed to indirectly beneficially own the securities of the Issuer directly held by the General Partner, but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F3 · shares: Pursuant to the Membership Interests Contributions Agreement among the Issuer, MPLX Logistics, MPLX Holdings, the General Partner and MPC Investment, on March 1, 2017, MPC Investment agreed to contribute the outstanding membership interests in Hardin Street Transportation LLC, Woodhaven Cavern LLC and MPLX Terminals LLC through a series of intercompany contributions to the Issuer for approximately $1.511 billion in cash and equity consideration valued at approximately $504 million, consisting of: (i) 9,197,900 common units issued to the General Partner, (ii) 2,630,427 common units issued to MPLX Logistics, (iii) 1,132,049 common units issued to MPLX Holdings and (iv) 264,497 general partner units issued to the General Partner. The common units and general partner units issued were calculated by dividing $503,750,000 by $38.0911, the simple average of the volume weighted average price of a common unit for the 10 trading days ending February 28, 2017.

F3 · price: Pursuant to the Membership Interests Contributions Agreement among the Issuer, MPLX Logistics, MPLX Holdings, the General Partner and MPC Investment, on March 1, 2017, MPC Investment agreed to contribute the outstanding membership interests in Hardin Street Transportation LLC, Woodhaven Cavern LLC and MPLX Terminals LLC through a series of intercompany contributions to the Issuer for approximately $1.511 billion in cash and equity consideration valued at approximately $504 million, consisting of: (i) 9,197,900 common units issued to the General Partner, (ii) 2,630,427 common units issued to MPLX Logistics, (iii) 1,132,049 common units issued to MPLX Holdings and (iv) 264,497 general partner units issued to the General Partner. The common units and general partner units issued were calculated by dividing $503,750,000 by $38.0911, the simple average of the volume weighted average price of a common unit for the 10 trading days ending February 28, 2017.

F1 · ownership.nature: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment LLC ("MPC Investment"), MPLX GP LLC (the "General Partner"), MPLX Logistics Holdings LLC ("MPLX Logistics") and MPLX Holdings Inc. ("MPLX Holdings"). MPC Investment, a direct wholly-owned subsidiary of MPC, owns all of the membership interests in both the General Partner and MPLX Logistics and all of the shares of stock of MPLX Holdings. Accordingly, the General Partner, MPLX Logistics and MPLX Holdings are indirect wholly-owned subsidiaries of MPC.

F2 · ownership.nature: The General Partner directly owns 7,636,916 general partner units, representing its 2% general partner interest in the Issuer. MPC Investment owns all of the membership interest in the General Partner and MPC owns all of the membership interest in MPC Investment. Accordingly, MPC and MPC Investment both may be deemed to indirectly beneficially own the securities of the Issuer directly held by the General Partner, but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F3 · ownership.nature: Pursuant to the Membership Interests Contributions Agreement among the Issuer, MPLX Logistics, MPLX Holdings, the General Partner and MPC Investment, on March 1, 2017, MPC Investment agreed to contribute the outstanding membership interests in Hardin Street Transportation LLC, Woodhaven Cavern LLC and MPLX Terminals LLC through a series of intercompany contributions to the Issuer for approximately $1.511 billion in cash and equity consideration valued at approximately $504 million, consisting of: (i) 9,197,900 common units issued to the General Partner, (ii) 2,630,427 common units issued to MPLX Logistics, (iii) 1,132,049 common units issued to MPLX Holdings and (iv) 264,497 general partner units issued to the General Partner. The common units and general partner units issued were calculated by dividing $503,750,000 by $38.0911, the simple average of the volume weighted average price of a common unit for the 10 trading days ending February 28, 2017.

SEC source: 0001209191-16-140307 · doc4.xml · nonDerivative · entry 1

Marathon Petroleum Corp · CIK 0001510295 · Director · 10% owner

MARKWEST HYDROCARBON L.L.C. · CIK 0001019756 · Director · 10% owner

MPC Investment LLC · CIK 0001560713 · Director · 10% owner

MPLX Holdings Inc. · CIK 0001683291 · Director · 10% owner

MPLX Logistics Holdings LLC · CIK 0001551994 · Director · 10% owner

MPLX GP LLC · CIK 0001551999 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

F1 · kind: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P., MWE GP LLC, MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F1 · shares: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P., MWE GP LLC, MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F2 · shares: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment, the General Partner, Logistics Holdings, Holdings and Hydrocarbon, with respect to the Issuer's Class A Units.

F3 · shares: The General Partner directly owns 7,193,467 general partner units, representing its 2% general partner interest in the Issuer. MPC Investment owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings, and MPC owns all of the membership interests in MPC Investment. Accordingly, MPC, MPC Investment and Holdings may be deemed to have indirectly beneficially owned the securities of the Issuer directly held by the General Partner, Logistics Holdings and Hydrocarbon but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F1 · price: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P., MWE GP LLC, MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F1 · ownership.nature: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P., MWE GP LLC, MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F2 · ownership.nature: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment, the General Partner, Logistics Holdings, Holdings and Hydrocarbon, with respect to the Issuer's Class A Units.

F3 · ownership.nature: The General Partner directly owns 7,193,467 general partner units, representing its 2% general partner interest in the Issuer. MPC Investment owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings, and MPC owns all of the membership interests in MPC Investment. Accordingly, MPC, MPC Investment and Holdings may be deemed to have indirectly beneficially owned the securities of the Issuer directly held by the General Partner, Logistics Holdings and Hydrocarbon but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

SEC source: 0001209191-16-140304 · doc4.xml · nonDerivative · entry 2

Marathon Petroleum Corp · CIK 0001510295 · Director · 10% owner

MARKWEST HYDROCARBON L.L.C. · CIK 0001019756 · Director · 10% owner

MPC Investment LLC · CIK 0001560713 · Director · 10% owner

MPLX Holdings Inc. · CIK 0001683291 · Director · 10% owner

MPLX Logistics Holdings LLC · CIK 0001551994 · Director · 10% owner

MPLX GP LLC · CIK 0001551999 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 86,619,313

F5 · kind: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among Holdings, MarkWest, MWE GP, MPLX, the General Partner, MPC Investment, Logistics Holdings and Hydrocarbon, all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly created and issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F2 · shares: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment, the General Partner, Logistics Holdings, Holdings and Hydrocarbon. MPC Investment, a direct wholly-owned subsidiary of MPC, owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, the General Partner, Logistics Holdings and Holdings are all indirect wholly-owned subsidiaries of MPC, and Hydrocarbon was an indirect wholly-owned subsidiary of MPC as of September 2, 2016.

F3 · shares: The General Partner directly owns 7,193,467 general partner units, representing a 2% general partner interest in the Issuer. MPC Investment owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings and MPC owns all of the membership interests in MPC Investment. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, MPC and MPC Investment both may be deemed to have indirectly beneficially owned the securities of the Issuer directly held by the General Partner, Logistics Holdings, Holdings and Hydrocarbon but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F4 · shares: The General Partner directly owns 7,193,467 general partner units, representing its 2% general partner interest in the Issuer.

F5 · shares: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among Holdings, MarkWest, MWE GP, MPLX, the General Partner, MPC Investment, Logistics Holdings and Hydrocarbon, all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly created and issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F5 · price: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among Holdings, MarkWest, MWE GP, MPLX, the General Partner, MPC Investment, Logistics Holdings and Hydrocarbon, all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly created and issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

F2 · ownership.nature: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment, the General Partner, Logistics Holdings, Holdings and Hydrocarbon. MPC Investment, a direct wholly-owned subsidiary of MPC, owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, the General Partner, Logistics Holdings and Holdings are all indirect wholly-owned subsidiaries of MPC, and Hydrocarbon was an indirect wholly-owned subsidiary of MPC as of September 2, 2016.

F3 · ownership.nature: The General Partner directly owns 7,193,467 general partner units, representing a 2% general partner interest in the Issuer. MPC Investment owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings and MPC owns all of the membership interests in MPC Investment. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, MPC and MPC Investment both may be deemed to have indirectly beneficially owned the securities of the Issuer directly held by the General Partner, Logistics Holdings, Holdings and Hydrocarbon but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F4 · ownership.nature: The General Partner directly owns 7,193,467 general partner units, representing its 2% general partner interest in the Issuer.

F5 · ownership.nature: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among Holdings, MarkWest, MWE GP, MPLX, the General Partner, MPC Investment, Logistics Holdings and Hydrocarbon, all issued and outstanding Class A Units representing limited partner interests of MPLX were exchanged for newly created and issued common units representing limited partner interests of MPLX on a one-to-one conversion, eliminating all issued and outstanding Class A Units representing limited partner interests of MPLX.

SEC source: 0001209191-16-140304 · doc4.xml · nonDerivative · entry 1

Marathon Petroleum Corp · CIK 0001510295 · Director · 10% owner

MARKWEST HYDROCARBON L.L.C. · CIK 0001019756 · Director · 10% owner

MPC Investment LLC · CIK 0001560713 · Director · 10% owner

MPLX Holdings Inc. · CIK 0001683291 · Director · 10% owner

MPLX Logistics Holdings LLC · CIK 0001551994 · Director · 10% owner

MPLX GP LLC · CIK 0001551999 · Director · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 58,064,999

F1 · kind: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P. ("MarkWest"), MWE GP LLC ("MWE GP"), MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), MPLX transferred 980 shares of Holdings common stock to Logistics Holdings in exchange for 21,401,137 common units held by Logistics Holdings.

F1 · shares: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P. ("MarkWest"), MWE GP LLC ("MWE GP"), MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), MPLX transferred 980 shares of Holdings common stock to Logistics Holdings in exchange for 21,401,137 common units held by Logistics Holdings.

F2 · shares: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment, the General Partner, Logistics Holdings, Holdings and Hydrocarbon. MPC Investment, a direct wholly-owned subsidiary of MPC, owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, the General Partner, Logistics Holdings and Holdings are all indirect wholly-owned subsidiaries of MPC, and Hydrocarbon was an indirect wholly-owned subsidiary of MPC as of September 2, 2016.

F3 · shares: The General Partner directly owns 7,193,467 general partner units, representing a 2% general partner interest in the Issuer. MPC Investment owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings and MPC owns all of the membership interests in MPC Investment. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, MPC and MPC Investment both may be deemed to have indirectly beneficially owned the securities of the Issuer directly held by the General Partner, Logistics Holdings, Holdings and Hydrocarbon but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F4 · shares: The General Partner directly owns 7,193,467 general partner units, representing its 2% general partner interest in the Issuer.

F1 · price: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P. ("MarkWest"), MWE GP LLC ("MWE GP"), MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), MPLX transferred 980 shares of Holdings common stock to Logistics Holdings in exchange for 21,401,137 common units held by Logistics Holdings.

F1 · ownership.nature: Pursuant to a Master Reorganization Agreement effective September 1, 2016 by and among MPLX Holdings Inc. ("Holdings"), MarkWest Energy Partners, L.P. ("MarkWest"), MWE GP LLC ("MWE GP"), MPLX LP ("MPLX"), MPLX GP LLC ("the "General Partner"), MPC Investment LLC ("MPC Investment"), MPLX Logistics Holdings LLC ("Logistics Holdings") and MarkWest Hydrocarbon, L.L.C. ("Hydrocarbon"), MPLX transferred 980 shares of Holdings common stock to Logistics Holdings in exchange for 21,401,137 common units held by Logistics Holdings.

F2 · ownership.nature: This Form 4 is filed jointly by Marathon Petroleum Corporation ("MPC"), MPC Investment, the General Partner, Logistics Holdings, Holdings and Hydrocarbon. MPC Investment, a direct wholly-owned subsidiary of MPC, owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, the General Partner, Logistics Holdings and Holdings are all indirect wholly-owned subsidiaries of MPC, and Hydrocarbon was an indirect wholly-owned subsidiary of MPC as of September 2, 2016.

F3 · ownership.nature: The General Partner directly owns 7,193,467 general partner units, representing a 2% general partner interest in the Issuer. MPC Investment owns all of the membership interests or stock in the General Partner, Logistics Holdings and Holdings and MPC owns all of the membership interests in MPC Investment. Holdings owned all of the membership interests in Hydrocarbon as of September 2, 2016. Accordingly, MPC and MPC Investment both may be deemed to have indirectly beneficially owned the securities of the Issuer directly held by the General Partner, Logistics Holdings, Holdings and Hydrocarbon but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F4 · ownership.nature: The General Partner directly owns 7,193,467 general partner units, representing its 2% general partner interest in the Issuer.