8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

Current Report

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) November 10, 2015

Marathon Petroleum Corporation

(Exact name of registrant as specified in its charter)

Delaware	001-35054	27-1284632
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification Number)

539 South Main Street Findlay, Ohio	45840-3229
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s telephone number, including area code:

(419) 422-2121

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 1.01 Entry into a Material Definitive Agreement.

Merger Agreement Amendment

On July 11, 2015, MPLX LP (“MPLX”), MarkWest Energy Partners, L.P. (“MWE”), MPLX GP LLC, the general partner of MPLX (“MPLX GP”), Sapphire Holdco LLC, a wholly owned subsidiary of MPLX (“Merger Sub”) and, for certain limited purposes set forth in the Merger Agreement (defined below), Marathon Petroleum Corporation, the indirect parent of MPLX and MPLX GP (“MPC”), entered into an agreement and plan of merger (the “Merger Agreement”), pursuant to which Merger Sub will merge with and into MWE, with MWE continuing as the surviving entity and becoming a wholly owned subsidiary of MPLX (the “Merger”). On November 10, 2015, MPLX, MPLX GP, MPC, MWE and Merger Sub entered into an amendment to the Merger Agreement (the “Amendment”) pursuant to which the cash portion of the proposed merger consideration was increased from $675 million in the aggregate to $1,075 million.

The Merger Agreement, as amended, provides that at the effective time of the Merger (the “Effective Time”), each common unit of MWE (each, a “Common Unit”) issued and outstanding as of immediately prior to the Effective Time will be converted into the right to receive (i)1.090 common units of MPLX representing limited partner interests in MPLX and (ii) cash in an amount obtained by dividing (A) $1,075 million by (B) the number of Common Units (including certain converted equity awards) plus the number of Class B units of MWE, in each case outstanding immediately prior to the Effective Time. The Merger is subject to certain customary conditions, including approval by MWE unitholders.

The foregoing description of the Amendment is qualified in its entirety by reference to the Amendment attached as Exhibit 2.1 to this Current Report on Form 8-K and incorporated herein by reference. A copy of the press release issued by MPC relating to the Amendment is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

As MPLX’s general partner, MPLX GP manages MPLX’s operations and activities through MPLX GP’s officers and directors. MPLX GP is an indirect wholly owned subsidiary of MPC. As a result, certain individuals serve as officers and directors of both MPLX GP and MPC. In addition, as of the date hereof, MPC holds, indirectly through its subsidiaries, 56,932,134 common units and 1,639,525 general partner units of MPLX, representing a 70.9% of the MPLX common units representing limited partner interests and a 2% general partner interest in MPLX.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit Number	Description
2.1	Amendment to Agreement and Plan of Merger, dated as of November 10, 2015, by and among MPLX, MPLX GP, MPC, MWE and Merger Sub.
99.1	Press Release dated November 10, 2015, issued by MPC.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Marathon Petroleum Corporation
Date: November 10, 2015	By:	/s/ J. Michael Wilder
	Name:	J. Michael Wilder
	Title:	Vice President, General Counsel and Secretary

Index to Exhibits

Exhibit Number	Description
2.1	Amendment to Agreement and Plan of Merger, dated as of November 10, 2015, by and among MPLX, MPLX GP, MPC, MWE and Merger Sub.
99.1	Press Release dated November 10, 2015, issued by MPC.

EX-2.1

Exhibit 2.1

EXECUTION VERSION

AMENDMENT TO AGREEMENT AND PLAN OF MERGER

THIS AMENDMENT TO AGREEMENT AND PLAN OF MERGER, dated as of November 10, 2015 (this “Amendment”), is made by and among MarkWest Energy Partners, L.P., a Delaware limited partnership (the “Partnership”), MPLX LP, a Delaware limited partnership (“Parent”), MPLX GP LLC, a Delaware limited liability company and the general partner of Parent (“Parent GP”), solely for purposes of Section 5.15 of the Merger Agreement (defined below), Marathon Petroleum Corporation, a Delaware corporation and the ultimate parent of Parent GP (“MPC”), and Sapphire Holdco LLC, a Delaware limited liability company and a wholly owned Subsidiary of Parent (“Merger Sub” and, with MPC, Parent and Parent GP, the “Parent Entities”).

RECITALS

1. The Parent Entities and the Partnership are parties to that certain Agreement and Plan of Merger, dated as of July 11, 2015 (the “Merger Agreement”).

2. Pursuant to Section 8.2 of the Merger Agreement, the Parent Entities and the Partnership desire to amend the Merger Agreement as set forth herein.

3. All capitalized terms used, but not defined, in this Amendment shall have the meanings ascribed thereto in the Merger Agreement.

4. In consideration of the foregoing, the representations, warranties, covenants and agreements set forth in this Amendment and the Merger Agreement, and other good and valuable consideration, the adequacy and receipt of which are hereby acknowledged, the parties, intending to be legally bound, hereby agree as follows:

SECTION 1. Amendments To The Merger Agreement. The parties hereby agree to amend the Merger Agreement as follows:

(a) Section 2.1(a) of the Merger Agreement is hereby amended by deleting the reference to $675,000,000 in the first and last sentences of Section 2.1(a) and replacing it with $1,075,000,000.

SECTION 2. Effectiveness of Amendment. Upon the execution and delivery of this Amendment, the Merger Agreement will thereupon be deemed to be amended as hereinabove set forth as fully and with the same effect as if the amendments made hereby were originally set forth in the Merger Agreement, and this Amendment and the Merger Agreement will henceforth respectively be read, taken and construed as one and the same instrument.

SECTION 3. Reaffirmation by the Parent Entities. Parent hereby makes and reaffirms the representations and warranties contained in Section 4.2(e) and Section 4.17 of the Merger Agreement, and MPC hereby reaffirms the covenants set forth in Section 5.15(b) of the Merger Agreement, after giving effect to the amendments effected pursuant to Section 1 hereof.

SECTION 4. Partnership Authority Relative to Amendment. The Partnership has all requisite power and authority to execute and deliver this Amendment and to consummate the transactions contemplated hereby, subject to obtaining the Partnership Unitholder Approval. The execution, delivery and performance by the Partnership of this Amendment, and the transactions contemplated hereby, have been duly authorized and approved by the General Partner, which, at a meeting duly called and held, has (i) approved and declared advisable this Amendment and the transactions contemplated hereby and (ii) resolved to submit the Merger Agreement, as amended by this Amendment, to a vote of the Limited Partners of the Partnership and to recommend approval of the Merger Agreement, as amended by this Amendment, by the Limited Partners of the Partnership, and except for obtaining the Partnership Unitholder Approval for the approval of the Merger Agreement, as amended by this Amendment, and consummation of the transactions contemplated hereby, no other partnership action on the part of the Partnership is necessary to authorize the execution, delivery and performance by the Partnership of this Amendment and the consummation of the transactions contemplated hereby. This Amendment has been duly executed and delivered by the Partnership and, assuming due authorization, execution and delivery, of this Amendment by the other parties hereto, constitutes a legal, valid and binding obligation of the Partnership, enforceable against it in accordance with its terms.

SECTION 5. Parent Entities Authority Relative to Amendment. Each of the Parent Entities has all requisite power and authority to execute and deliver this Amendment and to consummate the transactions contemplated hereby. The execution, delivery and performance by the Parent Entities of this Amendment, and the consummation of the transactions contemplated hereby, have been duly authorized and approved by Merger Sub and Parent, as its sole member, by Parent GP, for itself and on behalf of Parent, and by MPC and no other entity action on the part of the Parent Entities is necessary to authorize the execution, delivery and performance by the Parent Entities of this Amendment and the consummation of the transactions contemplated hereby. This Amendment has been duly executed and delivered by the Parent Entities and, assuming due authorization, execution and delivery of this Amendment by the Partnership, constitutes a legal, valid and binding obligation of each of the Parent Entities, enforceable against each of them in accordance with its terms.

SECTION 6. References to the Merger Agreement. After giving effect to this Amendment, each reference in the Merger Agreement to “this Agreement”, “hereof”, “hereunder”, “herein” or words of like import referring to the Merger Agreement shall refer to the Merger Agreement as amended by this Amendment, and all references in the Parent Disclosure Letter and the Partnership Disclosure Letter to “the Agreement” shall refer to the Merger Agreement as amended by this Amendment.

SECTION 7. Construction. Except as expressly provided in this Amendment, all references in the Merger Agreement, the Parent Disclosure Letter and the Partnership Disclosure Letter to “the date hereof” and “the date of this Agreement” or words of like import shall refer to July 11, 2015.

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SECTION 8. General Provisions.

(a) Miscellaneous. Sections 8.1 through 8.10 and Section 8.12 of the Merger Agreement are incorporated by reference into this Amendment and will apply to the Parent Entities and the Partnership mutatis mutandis.

(b) Agreement in Effect. Except as specifically provided for in this Amendment, the Merger Agreement will remain unmodified and in full force and effect.

[Signature Pages Follow]

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IN WITNESS WHEREOF, the parties have caused this Amendment to be duly executed and delivered as of the date first above written.

PARENT:
MPLX LP
By:	MPLX GP LLC, its general partner
By:	/s/ G.R. Heminger
Name: G.R. Heminger
Title: Chairman and Chief Executive Officer
PARENT GP:
MPLX GP LLC
By:	/s/ G.R. Heminger
Name: G.R. Heminger
Title: Chairman and Chief Executive Officer
MERGER SUB:
SAPPHIRE HOLDCO LLC
By:	/s/ P.K.M. Beall
Name: P.K.M. Beall
Title: President
MPC:
MARATHON PETROLEUM CORPORATION
By:	/s/ G.R. Heminger
Name: G.R. Heminger
Title: President and Chief Executive Officer

[Signature Page to Amendment to Merger Agreement]

PARTNERSHIP:
MARKWEST ENERGY PARTNERS, L.P.,
By:	MARKWEST ENERGY GP, L.L.C.,
	its general partner
By:	/s/ Frank M. Semple
Name:	Frank M. Semple
Title:	Chairman, President and Chief Executive Officer

[Signature Page to Amendment to Merger Agreement]

EX-99.1

Exhibit 99.1

Marathon Petroleum Corp. increases cash consideration for MPLX/MarkWest merger

• One-time cash payment from MPC raised to $1.075 billion from $675 million

• Total cash consideration of ~$5.21 per unit substantially enhances value to MarkWest unitholders

FINDLAY, Ohio, Nov. 10, 2015 – Marathon Petroleum Corporation (NYSE: MPC) today announced that it has agreed to contribute an additional $400 million of cash to MPLX LP (NYSE: MPLX), the midstream master limited partnership (MLP) sponsored by MPC, for a total cash contribution of $1.075 billion to fund a one-time cash payment to MarkWest unitholders in connection with the pending merger by which MarkWest Energy Partners, L.P. (NYSE: MWE) (MarkWest) would become a wholly owned subsidiary of MPLX. Under the revised terms of the merger agreement, MarkWest common unitholders will receive 1.09 MPLX common units plus a one-time cash payment of approximately $5.21 per MarkWest common unit, for a total consideration of approximately $52.93 per MarkWest common unit, based on fully diluted units currently outstanding and the closing price of MPLX’s common units on Nov. 10, 2015. The additional cash is being contributed to MPLX by MPC under which no new equity units will be issued to MPC, which is on the same basis as the original $675 million cash portion. MPC will also contribute approximately $225 million, based on the price of MPLX’s common units on Nov. 10, 2015, to maintain its 2 percent general partner interest in MPLX. These proceeds will be retained by the partnership to support its growth. All other terms of the merger agreement announced on July 13, 2015, remain the same.

The merger is recommended by the boards of directors of MPC, MPLX, and MarkWest, and the executive management of both partnerships also strongly support the transaction and its revised terms.

“The enhancement to the terms of the agreement reflects the commitment of MPC and MPLX to the combination with MarkWest and conviction that the transaction will create significant benefits for the unitholders, customers and employees of both partnerships,” said Gary R. Heminger, MPC president and chief executive officer. “This increase substantially enhances the transaction value for MarkWest unitholders, who will not only benefit from significant distribution growth, but also a substantially lower equity yield, investment-grade debt funding costs, enhanced access to capital and liquidity and a strong general partner prepared to provide support and financial flexibility.”

“MPC’s continuing support of the partnership reflects the substantial and growing value MPLX represents to the total enterprise and we are eager to continue the growth trajectory of MPLX with the combined partnership,” said Heminger.

The transaction is subject to approval by MarkWest unitholders and to customary closing conditions, and is expected to close in the fourth quarter of 2015. The special meeting of MarkWest common unitholders of record as of Oct. 5, 2015, to approve the transaction and related matters is scheduled for Dec. 1, 2015.

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About Marathon Petroleum Corporation

MPC is the nation’s fourth-largest refiner, with a crude oil refining capacity of approximately 1.7 million barrels per calendar day in its seven-refinery system. Marathon brand gasoline is sold through approximately 5,600 independently owned retail outlets across 19 states. In addition, Speedway LLC, an MPC subsidiary, owns and operates the nation’s second-largest convenience store chain, with approximately 2,760 convenience stores in 22 states. MPC also owns, leases or has ownership interests in approximately 8,300 miles of pipeline. Through subsidiaries, MPC owns the general partner of MPLX LP, a midstream master limited partnership. MPC’s fully integrated system provides operational flexibility to move crude oil, feedstocks and petroleum-related products efficiently through the company’s distribution network in the Midwest, Southeast and Gulf Coast regions. For additional information about the company, please visit our website at http://www.marathonpetroleum.com.

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Investor Relations Contacts:

Geri Ewing (419) 421-2071

Teresa Homan (419) 421-2965

Media Contact:

Chuck Rice (419) 421-2521

Forward-looking Statements

This press release contains forward-looking statements within the meaning of federal securities laws regarding Marathon Petroleum Corporation (“MPC”), MPLX LP (“MPLX”), and MarkWest Energy, L.P. (“MWE”). These forward-looking statements relate to, among other things, expectations, estimates and projections concerning the business and operations of MPC, MPLX, and MWE. You can identify forward-looking statements by words such as “anticipate,” “believe,” “estimate,” “objective,” “expect,” “forecast,” “guidance,” “imply”, “plan,” “project,” “potential,” “could,” “may,” “should,” “would,” “will” or other similar expressions that convey the uncertainty of future events or outcomes. Such forward-looking statements are not guarantees of future performance and are subject to risks, uncertainties and other factors, some of which are beyond the companies’ control and are difficult to predict. In addition to other factors described herein that could cause MPLX’s results to differ materially from those implied in these forward-looking statements, negative capital market conditions, including a persistence or increase of the current yield on common units, which is higher than historical yields, could adversely affect MPLX’s ability to meet its distribution growth guidance, particularly with respect to the later years of such guidance. Factors that could cause MPC’s actual results to differ materially from those implied in the forward-looking statements include: risks described below relating to the MPLX/MWE proposed merger; changes to the expected construction costs and timing of pipeline projects; volatility in and/or degradation of market and industry conditions; the availability and pricing of crude oil and other feedstocks; slower growth in domestic and Canadian crude supply; an easing or lifting of the U.S. crude oil export ban; completion of pipeline capacity to areas outside the U.S. Midwest; consumer demand for refined products; transportation logistics; the reliability of processing units and other equipment; MPC’s ability to successfully implement growth opportunities; modifications to MPLX earnings and distribution growth objectives; federal and state environmental, economic, health and safety, energy and other policies and regulations; changes to MPC’s capital budget; other risk factors inherent to MPC’s industry; and the factors set forth under the heading “Risk Factors” in MPC’s Annual Report on Form 10-K for the year ended Dec. 31, 2014, filed with Securities and Exchange Commission (SEC). Factors that could cause MPLX’s actual results to differ materially from those in the forward-looking statements include: the ability to complete the proposed merger of MPLX and MWE on anticipated terms and timetable; the ability to obtain approval of the transaction by the unitholders of MWE and satisfy other conditions to the closing of the transaction contemplated by the merger agreement; risk that the synergies from the MPLX/MWE transaction may not be fully realized or may take longer to realize than expected; disruption from the MPLX/MWE transaction making it more difficult to maintain relationships with customers, employees or suppliers; risks relating to any unforeseen liabilities of MWE or MPLX, as applicable; the adequacy of MPLX’s and MWE’s respective capital resources and liquidity, including, but not limited to, availability of sufficient cash flow to pay distributions, and the ability to successfully execute their business plans and implement their growth strategies; the timing and extent of changes in commodity prices and demand for crude oil, refined products, feedstocks or other hydrocarbon-based products; volatility in and/or degradation of market and industry conditions; completion of pipeline capacity by competitors; disruptions due to equipment interruption or failure, including electrical shortages and power grid failures; the suspension, reduction or termination of MPC’s obligations under MPLX’s commercial agreements; each company’s ability to successfully implement its growth plan, whether through organic growth or acquisitions; modifications to earnings and distribution growth objectives; federal and state environmental, economic, health and safety, energy and other policies and regulations; changes to MPLX’s capital budget; other risk factors inherent to MPLX or MWE’s industry; and the factors set forth under the heading “Risk Factors” in MPLX’s Annual Report on Form 10-K for the year ended Dec. 31, 2014, filed with the SEC; and the factors set forth under the heading “Risk Factors” in MWE’s Annual Report on Form 10-K for the year ended Dec. 31, 2014, and Quarterly Report on Form 10-Q for the quarter ended September 30, 2015, filed with the SEC.

These risks, as well as other risks associated with MPLX, MWE and the proposed transaction are also more fully discussed in the proxy statement and prospectus included in the registration statement on Form S-4 filed with the SEC by MPLX and declared effective by the SEC on October 29, 2015. In addition, the forward-looking statements included herein could be affected by general domestic and international economic and political conditions. Unpredictable or unknown factors not discussed here, in MPC’s Form 10-K, in MPLX’s Form 10-K, or in MWE’s Form 10-K could also have material adverse effects on forward-looking statements. Copies of MPC’s Form 10-K are available on the SEC website, MPC’s website at http://ir.marathonpetroleum.com or by contacting MPC’s Investor Relations office. Copies of MPLX’s Form 10-K are available on the SEC website, MPLX’s website at http://ir.mplx.com or by contacting MPLX’s Investor Relations office. Copies of MWE’s Form 10-K are available on the SEC website, MWE’s website at http://investor.markwest.com or by contacting MWE’s Investor Relations office.