MASTER REORGANIZATION AGREEMENT
This Master Reorganization Agreement (this “Agreement”) is entered into
effective as of September 1, 2016, by and among MPLX Holdings Inc., a Delaware
corporation (“Holdings”), MarkWest Energy Partners, L.P., a Delaware limited
partnership (“MarkWest”), MWE GP LLC, a Delaware limited liability company (“MWE
GP”), MPLX LP, a Delaware limited partnership (“MPLX”), MPLX GP LLC, a Delaware
limited liability company (“MPLX GP”), MPC Investment LLC, a Delaware limited
liability company (“MPC Investment”), MPLX Logistics Holdings LLC, a Delaware
limited liability company (“Logistics Holdings”), and MarkWest Hydrocarbon,
L.L.C., a Delaware limited liability company (“Hydrocarbon”). The parties hereto
are sometimes referred to, collectively, as the “Parties” and, individually, as
a “Party”.
RECITALS
WHEREAS, the Parties have decided to effect a series of Reorganization
Transactions (as defined below), including the exchange of all of the issued and
outstanding Class A units representing limited partner interests of MPLX (“MPLX
Class A Units”) for newly created and issued common units representing limited
partner interests of MPLX (“MPLX Common Units”) to, among other things, simplify
MPLX’s ownership structure by eliminating the MPLX Class A Units, simplify
MPLX’s financial and tax reporting, and facilitate the repayment of intercompany
debt between Hydrocarbon and MarkWest;
WHEREAS, prior to the date hereof, MPLX, MarkWest, Hydrocarbon and Holdings
entered into a Plan of Reorganization for purposes of Subchapter C of the United
States Internal Revenue Code of 1986, as amended (the “Code”), such that certain
steps qualify as reorganizations under Code § 368, pursuant to which Holdings
was formed, MarkWest contributed Hydrocarbon to Holdings, and Holdings converted
from a Delaware corporation to a Delaware limited liability company; and
WHEREAS, as of the date hereof and prior to giving effect to the transactions
contemplated by this Agreement:
(a)    Hydrocarbon owns 28,554,313 MPLX Class A Units, which represent all of
the MPLX Class A Units issued and outstanding;
(b)    Holdings is the sole member of Hydrocarbon;
(c)    MarkWest owns 1,000 shares of common stock of Holdings (“Holdings Common
Stock”), which represents all of the issued and outstanding capital stock of
Holdings;
(d)    MPLX owns 99 MarkWest common units representing limited partner interests
of MarkWest, which represent a 99% limited partner interest in MarkWest;

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(e)    MWE GP owns one MarkWest Class A unit representing general partner
interests of MarkWest, which represents a 1% general partner interest in
MarkWest;
(f)    MPLX is the sole member of MWE GP;
(g)    Logistics Holdings owns 79,466,136 MPLX Common Units;
(h)    MPLX GP owns 7,630,225 general partner units representing general partner
interests of MPLX (“MPLX GP Units”), which represent a 2% general partner
interest in MPLX; and
(i)    MPC Investment is the sole member of each of Logistics Holdings and MPLX
GP.
AGREEMENT
NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which are acknowledged by this Agreement, the Parties agree as follows:
ARTICLE 1
    REORGANIZATION TRANSACTIONS
1.1    Consent of the Parties. Subject to the terms of this Agreement and in
reliance upon the representations, warranties and covenants made herein, each
Party approves, authorizes and consents for all relevant purposes, including to
the extent that such approval, authorization and/or consent is required under
any Party’s constituency documents or applicable law, to each other Party taking
or causing to be taken any and all such actions necessary or proper to
consummate, give effect to and implement the Reorganization Transactions,
including, without limitation, (i) the execution, delivery and performance of
this Agreement and any other plan, contract, assignment, instrument, agreement,
certificate or other document necessary or proper to be executed, delivered or
performed in connection with this Agreement or the transactions contemplated
hereby or to otherwise give effect to the Reorganization Transactions
(collectively, the “Ancillary Documents”) to which such Party is a party, (ii)
the sale, assignment, transfer, contribution or distribution of any Interests
contemplated to be made hereunder or (iii) the filing of any of this Agreement
or any Ancillary Documents with the appropriate federal, state or local
governmental authorities.
1.2    Reorganization Transactions. The Parties agree to effect, or cause to be
effected, each of the following transactions (the “Reorganization
Transactions”), as applicable to the respective Party, in each case effective as
of the times and dates set forth below and, in any event, in the following
sequence, subject to the terms, conditions and limitations, if any, described
below:
(a)    Hydrocarbon will sell to Logistics Holdings, and Logistics Holdings will
purchase 2,500,000 MPLX Class A Units held by Hydrocarbon, effective on
September 1, 2016, at 11:56 p.m., for the purchase price payable in cash to
Hydrocarbon of $83,750,000.00, with such number of MPLX Class A Units purchased
calculated based on the simple average of the closing

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prices of MPLX Common Units as reported on the New York Stock Exchange (“NYSE”)
for the last ten trading days prior to September 1, 2016;
(b)    MarkWest will distribute (i) 990 shares of Holdings Common Stock,
representing a 99% ownership interest of Holdings, to MPLX, and (ii) 10 shares
of Holdings Common Stock, representing a 1% ownership interest of Holdings, to
MWE GP, in each case, effective on September 1, 2016, at 11:57 p.m.;
(c)    MWE GP will in turn distribute its 10 shares of Holdings Common Stock,
representing a 1% ownership interest of Holdings, to MPLX effective on September
1, 2016, at 11:57:30 p.m., after which distribution MPLX will own all 1,000
issued and outstanding shares of Holdings Common Stock;
(d)    MPLX will transfer (i) 980 shares of Holdings Common Stock, representing
a 98% ownership interest of Holdings, valued at $716,938,089.50 to Logistics
Holdings, in exchange for 21,401,137 MPLX Common Units held by Logistics
Holdings, which number of MPLX Common Units to be exchanged shall be calculated
based on the simple average of the closing prices of MPLX Common Units as
reported on the NYSE for the last ten trading days prior to September 1, 2016,
and (ii) 20 shares of Holdings Common Stock, representing a 2% ownership
interest of Holdings, valued at $14,631,393.00 to MPLX GP, in exchange for
436,758 MPLX GP Units held by MPLX GP, which number of MPLX GP Units to be
exchanged shall be calculated based on the simple average of the closing prices
of MPLX Common Units as reported on NYSE for the last ten trading days prior to
September 1, 2016, in each case, effective on September 1, 2016, at 11:58 p.m.;
(e)    Logistics Holdings will distribute 980 shares of Holdings Common Stock,
representing a 98% ownership interest of Holdings, to MPC Investment, effective
on September 1, 2016, at 11:59 p.m.;
(f)    MPLX GP will distribute 20 shares of Holdings Common Stock, representing
a 2% ownership interest of Holdings, to MPC Investment, effective on September
1, 2016, at 11:59 p.m., after which distribution, MPC Investment will own all
1,000 issued and outstanding shares of Holdings Common Stock;
(g)    MPLX will issue (i) MPLX Common Units to Hydrocarbon in exchange for all
of the MPLX Class A Units then held by Hydrocarbon and (ii) MPLX Common Units to
Logistics Holdings in exchange for all of the MPLX Class A Units then held by
Logistics Holdings, in each case based on a one-to-one (1:1) conversion and
effective on September 2, 2016, at 12:01 a.m., eliminating all issued and
outstanding MPLX Class A Units;
(h)    MPC Investment will contribute cash in the amount of $141,250,000.00 to
Holdings, effective on September 2, 2016, at 12:02 a.m.;
(i)    Holdings will in turn contribute cash in the amount of $141,250,000.00 to
Hydrocarbon, effective on September 2, 2016, at 12:03 a.m.;

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(j)    Hydrocarbon will transfer cash in the amount of $225,000,000.00 to
MarkWest in full payment and satisfaction of an intercompany loan owed by
Hydrocarbon to MarkWest, effective on September 2, 2016 at 12:03:30 a.m.;
(k)    Hydrocarbon will distribute to Holdings all of its MPLX Common Units
issued to Hydrocarbon, effective on September 2, 2016, at 12:04 a.m.;
(l)    Holdings will contribute its 100% ownership interest in Hydrocarbon to
MPLX in exchange for one newly created and issued MPLX Common Unit, effective on
September 2, 2016, at 12:05 a.m.;
(m)    MPLX will contribute (i) 99% of its ownership interest in Hydrocarbon to
MarkWest and (ii) 1% of its ownership interest in Hydrocarbon to MWE GP, in each
case, effective on September 2, 2016, at 12:06 a.m.; and
(n)    MWE GP will contribute its 1% ownership interest in Hydrocarbon to
MarkWest, effective on September 2, 2016, at 12:07 a.m.
ARTICLE 2
REPRESENTATIONS AND WARRANTIES
2.1    Mutual Representations. Each Party hereby represents and warrants to the
other Parties, as of the date hereof, that:
(a)    Such Party is an entity duly organized and validly existing under the
laws of the jurisdiction of its formation.
(b)    Such Party owns, beneficially and of record, its respective Interests
free and clear of all Liens and will transfer, sell, distribute or contribute
all right, title and interest in and to the Interests to the transferee free and
clear of all Liens as contemplated by Section 1.2. The Interests held by such
Party (and in the case of MPLX, the MPLX Common Units to be issued pursuant to
Section 1.2) are, or when issued will be, validly issued, fully paid, and
nonassessable (except as such nonassessability may be affected by Sections
18-607 and 18-804 of the Delaware Limited Liability Company Act or Sections
17-303, 17-607 and 17-804 of the Delaware Revised Uniform Limited Partnership
Act, if and to the extent applicable).
(c)    Such Party has the full power and authority and legal capacity to
execute, deliver and perform this Agreement and all other Ancillary Documents to
which it is a party and to consummate the transactions contemplated hereby and
thereby.
(d)    This Agreement and each Ancillary Documents to which such Party is a
party has been or will be duly authorized, executed and delivered and is a
legal, valid and binding obligation of such Party, enforceable against such
Party in accordance with its terms, subject to applicable bankruptcy, insolvency
and similar laws affecting creditors’ rights generally and to general principles
of equity.

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(e)    The execution and delivery and performance of this Agreement and each
Ancillary Document to which such Party is a party and the consummation of the
transactions contemplated hereby and thereby will not (with or without the
giving of notice, the lapse of time or both) materially conflict with, result in
a material breach of or constitute a material default or acceleration under, or
the creation of any Lien under (or result in an occurrence which with the lapse
of time or action by a third party or both could result in such a breach,
default or acceleration or the creation of a Lien) any of the terms, conditions
or provisions of any material contract, agreement or other material instrument
to which such Party is a party or by which it or its property may be materially
bound or affected or any law, statute, rule, regulation, ordinance, writ, order
or judgment to which such Party is subject or by which it or its property may be
materially bound or affected.
(f)    No approval, consent, waiver or filing of or with any person or entity,
including, but not limited to, any governmental authorities, bodies, agencies or
instrumentalities, is or will be required for the execution or delivery by such
Party of this Agreement or any Ancillary Document to which it is a party or the
consummation by such Party of the transactions contemplated hereby or thereby
other than approvals, consent, waivers or filings, if any, that have been or
will be timely obtained or satisfied or that, if not so obtained, would not be
reasonably be expected to have a material adverse effect on the consummation of
the transactions contemplated hereby.
(g)    There is no litigation, arbitration or administrative proceeding that is
taking place, pending, or to the knowledge of such Party threatened, against it
which could have a material adverse effect on such Party’s ability to enter into
this Agreement or any Ancillary Document to which it is a party or to consummate
the transactions contemplated hereby or thereby.
2.2    Effective Times. The Parties agree that payment of the amounts and the
issuance and/or delivery of the Interests to the appropriate Parties in
connection with the Reorganization Transactions will be deemed to have occurred
at the respective effective dates and times as provided in Section 1.2 even if
any such payments, issuances or deliveries actually occur prior to or following
such effective dates and times.
2.3    Survival. The representations and warranties of each of the Parties under
this Agreement shall survive until the fourth anniversary of the date of this
Agreement.
ARTICLE 3
DEFINITIONS
3.1    Definitions. As used in this Agreement, the following terms have the
following meanings:
“Affiliate” means, as to any specified entity, any other entity that, directly
or indirectly through one or more intermediaries or otherwise, controls, is
controlled by or is under common control with the specified entity. For purposes
of this definition, “control” of an entity means the possession, directly or
indirectly, of the power to direct or cause the direction of the management or
policies of such entity, whether by contract or otherwise. Notwithstanding
anything herein to the contrary, for the purposes of this Agreement, (a) the
MPLX Parties and their subsidiaries shall be

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deemed not to be “Affiliates” of the MPC Parties or any of their other
Affiliates, and (b) the MPC Parties and their respective Affiliates shall not be
deemed “Affiliates” of the MPLX Parties and their subsidiaries.
“Agreement” has the meaning set forth in the preamble.
“Ancillary Documents” has the meaning set forth in Section 1.1.
“Code” has the meaning set forth in the recitals.
“Holdings” has the meaning set forth in the preamble.
“Holdings Common Stock” has the meaning set forth in the recitals.
“Hydrocarbon” has the meaning set forth in the preamble.
“Interests” means the capital stock, voting securities, membership interests or
partnership units (whether general or limited) to be sold, assigned, transferred
or conveyed pursuant to Section 1.2.
“Liens” means any security interest, lien, deed of trust, mortgage, pledge,
charge, claim, restriction, easement, encumbrance or other similar interest or
right, provided that, restrictions on transfer of the Interests contained in the
relevant limited partnership agreement, limited liability company agreement,
bylaws or other applicable constituency document or imposed by applicable
securities laws and regulations will not be deemed Liens for purposes of this
Agreement.
“Logistics Holdings” has the meaning set forth in the preamble.
“MarkWest” has the meaning set forth in the preamble.
“MPC Investment” has the meaning set forth in the preamble.
“MPC Parties” means Holdings, MPLX GP, MPC Investment and Logistics Holdings.
“MPLX” has the meaning set forth in the preamble.
“MPLX GP” has the meaning set forth in the preamble.
“MPLX Class A Units” has the meaning set forth in the recitals.
“MPLX Common Units” has the meaning set forth in the recitals.
“MPLX GP Unit” has the meaning set forth in the recitals.
“MPLX Parties” means MarkWest, MWE GP, MPLX and Hydrocarbon.
“MWE GP” has the meaning set forth in the preamble.

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“Reorganization Transactions” has the meaning set forth in Section 1.2.
ARTICLE 4
MISCELLANEOUS

4.1    Successors and Assigns. Except as otherwise expressly provided herein,
all covenants and agreements contained in this Agreement by or on behalf of each
Party will bind and inure to the benefit of the respective successors and
assigns of such Party, whether so expressed or not.
4.2    Third Party Beneficiaries. This Agreement shall not confer any rights or
remedies upon any person not a Party.
4.3    Governing Law. All questions concerning the construction, validity and
interpretation of this Agreement will be governed by and construed in accordance
with the provisions of the internal laws of the State of Delaware, without
giving effect to any choice of law or conflict of law provision or doctrine that
would result in the application of the laws of another jurisdiction.
4.4    Severability. Whenever possible, each provision of this Agreement will be
interpreted in such manner as to be effective and valid under applicable law,
but if any provision of this Agreement is held to be prohibited by or invalid
under applicable law, such provision will be ineffective only to the extent of
such prohibition or invalidity, without invalidating the remainder of this
Agreement.
4.5    Entire Agreement. This Agreement, together with the Ancillary Agreements
constitute the complete and final agreement of the parties hereto concerning the
matters referred to herein and shall supersede all prior agreements and
understandings.
4.6    Execution in Counterparts. This Agreement may be executed in any number
of counterparts, each of which when so executed and delivered shall be deemed an
original, and such counterparts together shall constitute one instrument.
[Signature pages follow]

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IN WITNESS WHEREOF, the Parties have caused this Agreement to be duly executed
and delivered by their duly authorized representatives as of the time, day and
year first written above.
MARKWEST ENERGY PARTNERS, L.P.
By: MWE GP LLC, its General Partner
 
 
 
 
By:
/s/ Donald C. Templin
 
Name: Donald C. Templin
 
Title: President

MARKWEST HYDROCARBON, L.L.C.
 
 
 
 
By:
/s/ Donald C. Templin
 
Name: Donald C. Templin
 
Title: President

MPC INVESTMENT LLC
 
 
 
 
By:
/s/ Timothy T. Griffith
 
Name: Timothy T. Griffith
 
Title: Senior Vice President and Chief
 
Financial Officer

MPLX LP
By:
MPLX GP LLC, its General Partner
 
 
 
 
By:
/s/ Donald C. Templin
 
Name: Donald C. Templin
 
Title: President

MPLX GP LLC
 
 
 
 
By:
/s/ Nancy K. Buese
 
Name: Nancy K. Buese
 
Title: Executive Vice President and
 
      Chief Financial Officer

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MPLX HOLDINGS INC.
 
 
 
 
By:
/s/ Timothy T. Griffith
 
Name: Timothy T. Griffith
 
Title: Vice President

MPLX LOGISTICS HOLDINGS LLC
 
 
 
 
By:
/s/ Timothy T. Griffith
 
Name: Timothy T. Griffith
 
Title: Vice President

MWE GP LLC
 
 
 
 
By:
/s/ Nancy K. Buese
 
Name: Nancy K. Buese
 
Title: Executive Vice President and
 
      Chief Financial Officer

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