Marathon Petroleum Corp — Director's Dealing 2012

Nov 2, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MPLX LP (MPLX)
CIK: 0001552000
Period of Report: 2012-10-31

Reporting Person: Marathon Petroleum Corp (Director, 10% Owner)
Reporting Person: MPC Investment LLC (Director, 10% Owner)
Reporting Person: MPLX GP LLC (Director)
Reporting Person: MPLX Logistics Holdings LLC (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2012-10-31	Common Units (Limited Partner Interests)	A	17056515	—	Acquired	17056515	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-10-31	Subordinated Units (Limited Partner Interests)	$	A	36951515	Acquired		Common Units (36951515)	Indirect

Footnotes

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

F2: The General Partner owns a 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: Pursuant to the Contribution, Conveyance and Assumption Agreement effective October 31, 2012 by and among the Issuer, the General Partner, MPC Investment and various other affiliates of MPC and in connection with the closing of the initial public offering of the Issuer, MPC and its subsidiaries contributed certain assets to the Issuer and MPLX Logistics Holdings received: (i) 17,056,515 common units, representing a 22.6% limited partner interest in the Issuer and (ii) 36,951,515 subordinated units, representing a 49% limited partner interest in the Issuer, for a combined 71.6% limited partner interest in the Issuer. MPC and MPC Investment both may be deemed to indirectly beneficially own the securities of the Issuer directly held by MPLX Logistics Holdings, but disclaim beneficial ownership except to the extent of their respective pecuniary interests therein.

F4: The General Partner directly owns 1,508,225 general partner units, representing its 2% general partner interest in the Issuer.

F5: Each subordinated unit will convert into one common unit at the end of the subordination period described in the Issuer's Registration Statement on Form S-1 (Registration No. 333-182500).