Exhibit 4.2


 


Execution Version


 


May 26,
2009


 


REGISTRATION RIGHTS AGREEMENT


 


This REGISTRATION RIGHTS
AGREEMENT dated May 26, 2009 (this “Agreement”) is entered
into by and among MarkWest Energy Partners L.P., a limited partnership
organized under the laws of the State of Delaware (the “Partnership”),
MarkWest Energy Finance Corporation, a corporation organized under the laws of
the State of Delaware (“Finance Corp” and, together with the
Partnership, the “Issuers”), the guarantors  listed
on the signature pages hereto (the “Guarantors”), and J.P. Morgan Securities Inc., RBC Capital
Markets Corporation, Wachovia Capital Markets, LLC, Deutsche Bank Securities
Inc., and U.S. Bancorp Investments, Inc. (collectively, the “Initial
Purchasers”).


 


The Issuers, the Guarantors
and the Initial Purchasers are parties to that certain Purchase Agreement dated
May 20, 2009 (the “Purchase Agreement”), which provides for the
sale by the Issuers to the Initial Purchasers of $150,000,000 aggregate
principal amount of the Issuers’ 6.875% Senior Notes due 2014 (the “Securities”)
that will be guaranteed on an unsecured senior basis by each of the
Guarantors.  The Securities will be
issued pursuant to an Indenture, dated as of May 26, 2009, among the
Issuers, the Guarantors and Wells Fargo Bank, National Association, as trustee
(the “Indenture”).  As an
inducement to the Initial Purchasers to enter into the Purchase Agreement, the
Issuers and the Guarantors have agreed to provide to the Initial Purchasers and
their direct and indirect transferees the registration rights set forth in this
Agreement.  The execution and delivery of
this Agreement is a condition to the closing under the Purchase Agreement.


 


In consideration of the
foregoing, the parties hereto agree as follows:


 


1.             Definitions.  As used in this Agreement, the following
terms shall have the following meanings:


 


“Business
Day” shall have the meaning ascribed thereto in the Indenture.


 


“DTC” shall mean
the Depository Trust Company.


 


“Exchange Act”
shall mean the Securities Exchange Act of 1934, as amended from time to time.


 


“Exchange Dates”
shall have the meaning set forth in Section 2(a)(ii) hereof.


 


“Exchange
Offer” shall mean the exchange offer by the Issuers and the Guarantors of
Exchange Securities for Registrable Securities pursuant to Section 2(a) hereof.


 


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“Exchange Offer
Registration” shall mean a registration under the Securities Act effected
pursuant to Section 2(a) hereof.


 


“Exchange Offer
Registration Statement” shall mean an exchange offer registration statement
on Form S-4 (or, if applicable, on another appropriate form) and all
amendments and supplements to such registration statement, in each case
including the Prospectus contained therein, all exhibits thereto and any
document incorporated by reference therein.


 


“Exchange Securities”
shall mean senior notes issued by the Issuers and guaranteed by the Guarantors
under the Indenture containing terms identical to the Securities (except that
the Exchange Securities will not be subject to restrictions on transfer or to
any increase in annual interest rate for failure to comply with this Agreement)
and to be offered to Holders of Securities in exchange for Securities pursuant
to the Exchange Offer.


 


“Finance Corp”
shall have the meaning set forth in the preamble and shall also include Finance
Corp’s successors.


 


“FINRA” shall mean
the Financial Industry
Regulatory Authority, Inc.


 


“Guarantors” shall
have the meaning set forth in the preamble and shall also include any Guarantor’s
successors.


 


“Holders” shall
mean the Initial Purchasers, for so long as they own any Registrable
Securities, and each of their successors, assigns and direct and indirect
transferees who become owners of Registrable Securities under the Indenture;
provided that for purposes of Sections 4 and 5 of this Agreement, the term “Holders”
shall include Participating Broker-Dealers.


 


“Indemnified Person”
shall have the meaning set forth in Section 5(c) hereof.


 


“Indemnifying Person”
shall have the meaning set forth in Section 5(c) hereof.


 


“Indenture” shall
have the meaning set forth in the recital.


 


“Initial Purchasers”
shall have the meaning set forth in the preamble.


 


“Inspector” shall
have the meaning set forth in Section 3(a)(xiii) hereof.


 


“Issuer FWP” shall
have the meaning set forth in Section 5(a) hereof.


 


“Issuers” shall
have the meaning set forth in the preamble.


 


“Majority Holders”
shall mean the Holders of a majority of the aggregate principal amount of the
outstanding Registrable Securities; provided that whenever the 


 


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consent or approval of Holders of a specified percentage of Registrable
Securities is required hereunder, any Registrable Securities owned directly or
indirectly by the Issuers or any of their affiliates shall not be counted in
determining whether such consent or approval was given by the Holders of such
required percentage or amount; and provided, further, that if the Issuers shall
issue any additional Securities under the Indenture prior to consummation of
the Exchange Offer or, if applicable, the effectiveness of any Shelf
Registration Statement, such additional Securities and the Registrable
Securities to which this Agreement relates shall be treated together as one
class for purposes of determining whether the consent or approval of Holders of
a specified percentage of Registrable Securities has been obtained.


 


“Participating
Broker-Dealers” shall have the meaning set forth in Section 4(a) hereof.


 


“Partnership”
shall have the meaning set forth in the preamble and shall also include the
Partnership’s successors.


 


“Person” shall
mean an individual, partnership, limited liability company, corporation, trust
or unincorporated organization, or a government or agency or political subdivision
thereof.


 


“Prospectus” shall
mean the prospectus included in a Registration Statement, including any
preliminary prospectus, and any such prospectus as amended or supplemented by
any prospectus supplement, including a prospectus supplement with respect to
the terms of the offering of any portion of the Registrable Securities covered
by a Shelf Registration Statement, and by all other amendments and supplements
to such prospectus, and in each case including any document incorporated by
reference therein.


 


“Purchase Agreement”
shall have the meaning set forth in the recital.


 


“Registrable
Securities” shall mean the Securities; provided that the Securities shall
cease to be Registrable Securities (i) when a Registration Statement with
respect to such Securities has been declared effective under the Securities Act
and such Securities have been exchanged or disposed of pursuant to such
Registration Statement, (ii) when such Securities are freely tradeable
pursuant to Rule 144 (or any similar provision then in force, but not Rule 144A)
under the Securities Act by Persons other than any affiliate of either of the
Issuers (as such term is defined in Rule 144) or (iii) when such
Securities cease to be outstanding.


 


“Registration Expenses”
shall mean any and all expenses incident to performance of or compliance by the
Issuers and the Guarantors with this Agreement, including without limitation: (i) all
SEC, stock exchange or
FINRA registration and filing fees, (ii) all fees and expenses incurred in
connection with compliance with state securities or blue sky laws
(including reasonable fees and disbursements of counsel for any Underwriters or
Holders in connection with blue sky qualification of any Exchange Securities or
Registrable Securities), (iii) all expenses of any Persons in preparing or
assisting in 


 


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preparing, word processing, printing and distributing any Registration
Statement, any Prospectus and any amendments or supplements thereto, any
underwriting agreements, securities sales agreements or other similar
agreements and any other documents relating to the performance of and
compliance with this Agreement, (iv) all rating agency fees, (v) all
fees and disbursements relating to the qualification of the Indenture under
applicable securities laws, including without limitation the Trust Indenture
Act, (vi) the fees and disbursements of the Trustee and its counsel, (vii) the
fees and disbursements of counsel for the Issuers and the Guarantors and, in
the case of a Shelf Registration Statement, the fees and disbursements of one
counsel for the Holders (which counsel shall be selected by the Majority
Holders and which counsel may also be counsel for the Initial Purchasers) and (viii) the
fees and disbursements of the independent public accountants of the Issuers and
the Guarantors, including the expenses of any special audits or “comfort”
letters required by or incident to the performance of and compliance with this
Agreement, but excluding fees and expenses of counsel to the Underwriters
(other than fees and expenses set forth in clause (ii) above) or the
Holders and underwriting discounts and commissions, brokerage commissions and
transfer taxes, if any, relating to the sale or disposition of Registrable
Securities by a Holder.


 


“Registration
Statement” shall mean any registration statement of the Issuers and the
Guarantors that covers any of the Exchange Securities or Registrable Securities
pursuant to the provisions of this Agreement and all amendments and supplements
to any such registration statement, including post-effective amendments, in
each case including the Prospectus contained therein, all exhibits thereto and
any document incorporated by reference therein.


 


“SEC” shall mean
the United States Securities and Exchange Commission.


 


“Securities” shall
have the meaning set forth in the recital.


 


“Securities Act”
shall mean the Securities Act of 1933, as amended from time to time.


 


“Shelf Effectiveness
Period” shall have the meaning set forth in Section 2(b) hereof.


 


“Shelf Registration”
shall mean a registration effected pursuant to Section 2(b) hereof.


 


“Shelf Registration
Statement” shall mean a “shelf” registration statement of the Issuers and
the Guarantors that covers all or a portion of the Registrable Securities (but
no other securities unless approved by the Holders of a majority of the
Registrable Securities to be covered by such Shelf Registration Statement) on
an appropriate form under Rule 415 under the Securities Act, or any
similar rule that may be adopted by the SEC, and all amendments and
supplements to such registration statement, including post-effective
amendments, in each case including the Prospectus contained therein, all
exhibits thereto and any document incorporated by reference therein.


 


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“Staff” shall mean
the staff of the SEC.


 


“Target Registration
Date” shall have the meaning set for in Section 2(d) hereof.


 


“Trust Indenture Act”
shall mean the Trust Indenture Act of 1939, as amended from time to time.


 


“Trustee” shall
mean the trustee with respect to the Securities under the Indenture.


 


“Underwriter”
shall have the meaning set forth in Section 3(f) hereof.


 


“Underwritten Offering”
shall mean an offering in which Registrable Securities are sold to an
Underwriter for reoffering to the public.


 


2.             Registration Under
the Securities Act.  (a)  To the
extent not prohibited by any applicable law or applicable interpretations of
the Staff, the Issuers and the Guarantors shall use their reasonable best
efforts to cause to be filed an Exchange Offer Registration Statement covering
an offer to the Holders to exchange all the Registrable Securities for Exchange
Securities.  The Issuers and the
Guarantors shall commence the Exchange Offer promptly after the Exchange Offer
Registration Statement is declared effective by the SEC and use their
reasonable best efforts to complete the Exchange Offer not later than 60 days
after such effective date.


 


The Issuers and the
Guarantors shall commence the Exchange Offer by mailing the related Prospectus,
appropriate letters of transmittal and other accompanying documents to each
Holder stating, in addition to such other disclosures as are required by
applicable law, substantially the following:


 


(i)            that
the Exchange Offer is being made pursuant to this Agreement and that all
Registrable Securities validly tendered and not properly withdrawn will be
accepted for exchange;


 


(ii)           the
dates of acceptance for exchange (which shall be a period of at least 20
Business Days from the date such notice is mailed) (the “Exchange Dates”);


 


(iii)          that any Registrable Security not tendered
will remain outstanding and continue to accrue interest but will not retain any
rights under this Agreement;


 


(iv)          that
any Holder electing to have a Registrable Security exchanged pursuant to the
Exchange Offer will be required, (x) in the case a Holder electing to
exchange a Registrable Security in global form, to comply with the applicable
procedures of DTC for book-entry tenders, and, (y) in the case of a Holder
electing to exchange a Registrable Security in certificated form, to surrender
such Registrable Security, together with the appropriate letters of
transmittal, to the institution and at the address (located in the Borough of
Manhattan, The City of New York) and in the 


 


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manner specified
in the notice, prior to the close of business on the last Exchange Date; and


 


(v)           that
any Holder will be entitled to withdraw its election, not later than the close
of business on the last Exchange Date, by, (x) in the case of a Holder
withdrawing its election to exchange a Registrable Security in global form,
complying with the applicable procedures of DTC for withdrawal of tenders, and,
(y) in the case of a Holder withdrawing its election to exchange a
Registrable Security in certificated form, sending to the institution and at
the address (located in the Borough of Manhattan, The City of New York)
specified in the notice, a telegram, facsimile transmission or letter setting
forth the name of such Holder, the principal amount of Registrable Securities
delivered for exchange and a statement that such Holder is withdrawing its
election to have such Securities exchanged.


 


As a condition to participating in the Exchange Offer, a
Holder will be required to represent to the Issuers and the Guarantors that (i) any
Exchange Securities to be received by it will be acquired in the ordinary
course of its business, (ii) at the time of the commencement of the Exchange
Offer it has no arrangement or understanding with any Person to participate in
the distribution (within the meaning of the Securities Act) of the Exchange
Securities in violation of the provisions of the Securities Act, (iii) it
is not an “affiliate” (within the meaning of Rule 405 under the Securities
Act) of either of the Issuers or any Guarantor and (iv) if such Holder is
a broker-dealer that will receive Exchange Securities for its own account in
exchange for Registrable Securities that were acquired as a result of
market-making or other trading activities, then such Holder will deliver a
Prospectus in connection with any resale of such Exchange Securities.


 


As soon as practicable
after the last Exchange Date, the Issuers and the Guarantors shall:


 


(i)            accept
for exchange Registrable Securities or portions thereof validly tendered and
not properly withdrawn pursuant to the Exchange Offer; and


 


(ii)           deliver,
or cause to be delivered, to the Trustee for cancellation all Registrable
Securities or portions thereof so accepted for exchange by the Issuers and
issue, and cause the Trustee to promptly authenticate and deliver to each
Holder, Exchange Securities equal in principal amount to the principal amount
of the Registrable Securities surrendered by such Holder.


 


The Issuers and the
Guarantors shall use their reasonable best efforts to complete the Exchange
Offer as provided above and shall comply with the applicable requirements of
the Securities Act, the Exchange Act and other applicable laws and regulations
in connection with the Exchange Offer. 
The Exchange Offer shall not be subject to any conditions, other than
that the Exchange Offer does not violate any applicable law or applicable
interpretations of the Staff.


 


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(b)           In the event that (i) the
Issuers and the Guarantors determine that the Exchange Offer Registration
provided for in Section 2(a) above is not available or may not be
completed as soon as practicable after the last Exchange Date because it would
violate any applicable law or applicable interpretations of the Staff, (ii) the
Exchange Offer is not for any other reason completed by November 26, 2009
or (iii) any Initial Purchaser
shall so request in connection with any offer or sale of Registrable Securities
that are not eligible to be exchanged for Exchange Securities, the
Issuers and the Guarantors shall use their reasonable best efforts to cause to
be filed as soon as practicable after such determination, date or request, as
the case may be, a Shelf Registration Statement providing for the sale of all
the Registrable Securities by the Holders thereof and to have such Shelf
Registration Statement declared effective by the SEC.


 


In the event that the
Issuers and the Guarantors are required to file a Shelf Registration Statement
pursuant to clause (iii) of the preceding sentence, the Issuers and the
Guarantors shall use their reasonable best efforts to file and have declared
effective by the SEC both an Exchange Offer Registration Statement pursuant to Section 2(a) with
respect to all Registrable Securities and a Shelf Registration Statement (which
may be a combined Registration Statement with the Exchange Offer Registration
Statement) with respect to offers and sales of Registrable Securities held by
the Initial Purchasers after completion of the Exchange Offer.


 


The Issuers and the
Guarantors agree to use their reasonable best efforts to keep the Shelf
Registration Statement continuously effective for one year, or such shorter
period that will terminate when all the Registrable Securities covered by the
Shelf Registration Statement have been sold pursuant to the Shelf Registration
Statement (the “Shelf Effectiveness Period”).  The Issuers and the Guarantors further agree
to supplement or amend the Shelf Registration Statement and the related
Prospectus if required by the rules, regulations or instructions applicable to
the registration form used by the Issuers for such Shelf Registration Statement
or by the Securities Act or by any other rules and regulations thereunder
for shelf registration or if reasonably requested by a Holder of Registrable
Securities with respect to information relating to such Holder, and to use
their reasonable best efforts to cause any such amendment to become effective and
such Shelf Registration Statement and Prospectus to become usable as soon as
thereafter practicable.  The Issuers and
the Guarantors agree to furnish to the Holders of Registrable Securities copies
of any such supplement or amendment promptly after its being used or filed with
the SEC.


 


(c)           The Issuers and the
Guarantors shall pay all Registration Expenses in connection with any
registration pursuant to Section 2(a) or Section 2(b) hereof.  Each Holder shall pay all underwriting
discounts and commissions, brokerage commissions and transfer taxes, if any,
relating to the sale or disposition of such Holder’s Registrable Securities
pursuant to the Shelf Registration Statement.


 


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(d)           An Exchange Offer
Registration Statement pursuant to Section 2(a) hereof or a Shelf
Registration Statement pursuant to Section 2(b) hereof will not be
deemed to have become effective unless it has been declared effective by the
SEC.


 


In the event that either
the Exchange Offer is not completed or the Shelf Registration Statement, if
required hereby, is not declared effective on or prior to November 26,
2009 (the “Target Registration Date”), the interest rate on the
Registrable Securities will be increased by (i) 0.50% per annum for the
first 90-day period immediately following the Target Registration Date and (ii) an
additional 0.25% per annum with respect to each subsequent 90-day period, in
each case until the Exchange Offer is completed or the Shelf Registration
Statement, if required hereby, is declared effective by the SEC no longer
qualify as Registrable Securities, up to a maximum of 1.00% per annum of
additional interest; provided that if an obligation to file a Shelf
Registration Statement arises pursuant to Section 2(b)(iii) and the
applicable Initial Purchaser does not make the request to file a Shelf
Registration Statement by September 28, 2009, then the Target Registration
Date shall be extended by the number of days from and including September 28,
2009 to and including the date on which such request is made.


 


                If the Shelf
Registration Statement, if required hereby, has been declared effective and
thereafter either ceases to be effective or the Prospectus contained therein
ceases to be usable at any time during the Shelf Effectiveness Period, and such
failure to remain effective or usable exists for more than 60 days (whether or
not consecutive) in any 12-month period, then the interest rate on the
Registrable Securities will be increased by (i) 0.50% per annum commencing
on the 61st day in such 12-month period and (ii) an additional 0.25% per
annum with respect to each subsequent 90-day period (whether or not
consecutive) and ending on such date that the Shelf Registration Statement has
again been declared effective or the Prospectus again becomes usable, up to a
maximum of 1.00% per annum of additional interest.


 


(e)           Without limiting the
remedies available to the Initial Purchasers and the Holders, the Issuers and
the Guarantors acknowledge that any failure by the Issuers or the Guarantors to
comply with their obligations under Section 2(a) and Section 2(b) hereof
may result in material irreparable injury to the Initial Purchasers or the
Holders for which there is no adequate remedy at law, that it will not be
possible to measure damages for such injuries precisely and that, in the event
of any such failure, the Initial Purchasers or any Holder may obtain such
relief as may be required to specifically enforce the Issuers’ and the
Guarantors’ obligations under Section 2(a) and Section 2(b) hereof.


 


3.             Registration
Procedures.  (a) In connection
with their obligations pursuant to Section 2(a) and Section 2(b) hereof,
the Issuers and the Guarantors shall as expeditiously as possible:


 


(i)            prepare and file with
the SEC a Registration Statement on the appropriate form under the Securities
Act, which form (x) shall be selected by the Issuers and the Guarantors, (y) shall,
in the case of a Shelf Registration, be available for the sale of the 


 


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Registrable Securities by the Holders thereof and (z) shall comply
as to form in all material respects with the requirements of the applicable
form and include all financial statements required by the SEC to be filed
therewith; and use their reasonable best efforts to cause such Registration
Statement to become effective and remain effective for the applicable period in
accordance with Section 2 hereof;


 


(ii)           prepare and file with
the SEC such amendments and post-effective amendments to each Registration
Statement as may be necessary to keep such Registration Statement effective for
the applicable period in accordance with Section 2 hereof and cause each
Prospectus to be supplemented by any required prospectus supplement and, as so
supplemented, to be filed pursuant to Rule 424 under the Securities Act;
and keep each Prospectus current during the period described in Section 4(3) of
and Rule 174 under the Securities Act that is applicable to transactions
by brokers or dealers with respect to the Registrable Securities or Exchange
Securities;


 


(iii)          in the case of a Shelf
Registration, furnish to each Holder of Registrable Securities, to counsel for
the Initial Purchasers, to counsel for such Holders and to each Underwriter of
an Underwritten Offering of Registrable Securities, if any, without charge, as
many copies of each Prospectus, including each preliminary Prospectus, and any
amendment or supplement thereto, in order to facilitate the sale or other
disposition of the Registrable Securities thereunder; and the Issuers and the
Guarantors consent to the use of such Prospectus and any amendment or
supplement thereto in accordance with applicable law by each of the Holders of
Registrable Securities and any such Underwriters in connection with the offering
and sale of the Registrable Securities covered by and in the manner described
in such Prospectus or any amendment or supplement thereto in accordance with
applicable law;


 


(iv)          use their reasonable
best efforts to register or qualify the Registrable Securities under all
applicable state securities or blue sky laws of such jurisdictions in the
United States as any Holder of Registrable Securities covered by a Registration
Statement shall reasonably request in writing by the time the applicable
Registration Statement is declared effective by the SEC; cooperate with such
Holders in connection with any filings required to be made with FINRA; and do any and all other acts
and things that may be reasonably necessary or advisable to enable each Holder
to complete the disposition in each such jurisdiction of the Registrable
Securities owned by such Holder; provided that none of the Issuers or
the Guarantors shall be required to (1) qualify as a foreign corporation
or other entity or as a dealer in securities in any such jurisdiction where it
would not otherwise be required to so qualify, (2) file any general
consent to service of process in any such jurisdiction or (3) subject
itself to taxation in any such jurisdiction if it is not so subject;


 


(v)           in the case of a Shelf
Registration, notify each Holder of Registrable Securities, counsel for such
Holders and counsel for the Initial Purchasers promptly and, if requested by
any such Holder or counsel, confirm such advice in writing (1) when a
Registration Statement has become effective and when any post-effective
amendment thereto has been filed and becomes effective, (2) of any request
by the SEC or any state 


 


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securities authority for amendments and supplements to a Registration
Statement and Prospectus or for additional information after the Registration
Statement has become effective, (3) of the issuance by the SEC or any
state securities authority of any stop order suspending the effectiveness of a
Registration Statement or the initiation of any proceedings for that purpose, (4) if,
between the effective date of a Registration Statement and the closing of any
sale of Registrable Securities covered thereby, the representations and
warranties of either of the Issuers or any Guarantor contained in any
underwriting agreement, securities sales agreement or other similar agreement,
if any, relating to an offering of such Registrable Securities cease to be true
and correct in all material respects or if either of the Issuers or any
Guarantor receives any notification with respect to the suspension of the
qualification of the Registrable Securities for sale in any jurisdiction or the
initiation of any proceeding for such purpose, (5) of the happening of any
event during the period a Shelf Registration Statement is effective that makes
any statement made in such Registration Statement or the related Prospectus
untrue in any material respect or that requires the making of any changes in
such Registration Statement or Prospectus in order to make the statements
therein not misleading and (6) of any determination by either of the
Issuers or any Guarantor that a post-effective amendment to a Registration
Statement would be appropriate;


 


(vi)          use their reasonable
best efforts to obtain the withdrawal of any order suspending the effectiveness
of a Registration Statement at the earliest possible moment and provide
immediate notice to each Holder of the withdrawal of any such order;


 


(vii)         in the case of a Shelf
Registration, furnish to each Holder of Registrable Securities, without charge,
at least one conformed copy of each Registration Statement and any
post-effective amendment thereto (without any documents incorporated therein by
reference or exhibits thereto, unless requested);


 


(viii)        in the case of a Shelf
Registration, cooperate with the Holders of any Registrable Securities in
certificated form to facilitate the timely preparation and delivery of
certificates representing Registrable Securities to be sold and not bearing any
restrictive legends and enable such Registrable Securities to be issued in such
denominations and registered in such names (consistent with the provisions of
the Indenture) as such Holders may reasonably request at least one Business Day
prior to the closing of any sale of Registrable Securities in certificated
form;


 


(ix)           in the case of a Shelf
Registration, upon the occurrence of any event contemplated by Section 3(a)(v)(5) hereof,
use their reasonable best efforts to prepare and file with the SEC a supplement
or post-effective amendment to such Shelf Registration Statement or the related
Prospectus or any document incorporated therein by reference or file any other
required document so that, as thereafter delivered to purchasers of the
Registrable Securities, such Prospectus will not contain any untrue statement
of a material fact or omit to state a material fact necessary to make the
statements therein, in the light of the circumstances under which they were
made, not misleading; and the Issuers and the Guarantors shall notify the
Holders of Registrable Securities to suspend use of the Prospectus as promptly
as practicable after the occurrence of such an event,


 


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and such Holders hereby
agree to suspend use of the Prospectus until the Issuers and the Guarantors
have amended or supplemented the Prospectus to correct such misstatement or
omission;


 


(x)            a reasonable time
prior to the filing of any Registration Statement, any Prospectus, any
amendment to a Registration Statement or amendment or supplement to a
Prospectus or of any document that is to be incorporated by reference into a
Registration Statement or a Prospectus after initial filing of a Registration
Statement, provide copies of such document to the Initial Purchasers and their
counsel (and, in the case of a Shelf Registration Statement, to the Holders of
Registrable Securities and their counsel) and make such of the representatives
of the Issuers and the Guarantors as shall be reasonably requested by the
Initial Purchasers or their counsel (and, in the case of a Shelf Registration
Statement, the Holders of Registrable Securities or their counsel) available
for discussion of such document; and the Issuers and the Guarantors shall not,
at any time after initial filing of a Registration Statement, file any
Prospectus, any amendment of or supplement to a Registration Statement or a
Prospectus, or any document that is to be incorporated by reference into a
Registration Statement or a Prospectus, of which the Initial Purchasers and
their counsel (and, in the case of a Shelf Registration Statement, the Holders
of Registrable Securities and their counsel) shall not have previously been
advised and furnished a copy or to which the Initial Purchasers or their
counsel (and, in the case of a Shelf Registration Statement, the Holders of
Registrable Securities or their counsel) shall object; provided, that
this clause shall not apply to any filing by the Partnership of any Annual
Report on Form 10-K, Quarterly Report on Form 10-Q or Current Report
on Form 8-K with respect to matters unrelated to the Securities and the
offering or exchange therefor;


 


(xi)           obtain a CUSIP number
for all Exchange Securities or Registrable Securities, as the case may be, not
later than the effective date of a Registration Statement;


 


(xii)          cause the Indenture to
be qualified under the Trust Indenture Act in connection with the registration
of the Exchange Securities or Registrable Securities, as the case may be;
cooperate with the Trustee and the Holders to effect such changes to the
Indenture as may be required for the Indenture to be so qualified in accordance
with the terms of the Trust Indenture Act; and execute, and use their
reasonable best efforts to cause the Trustee to execute, all documents as may
be required to effect such changes and all other forms and documents required
to be filed with the SEC to enable the Indenture to be so qualified in a timely
manner;


 


(xiii)         in the case of a Shelf
Registration, make available for inspection by a representative of the Holders
of the Registrable Securities (an “Inspector”), any Underwriter
participating in any disposition pursuant to such Shelf Registration Statement,
any attorneys and accountants designated by the Holders of Registrable
Securities and any attorneys and accountants designated by such Underwriter, at
reasonable times and in a reasonable manner, all pertinent financial and other
records, documents and properties of the Issuers and the Guarantors, and cause
the respective 


 


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officers, directors and employees of the Issuers and the Guarantors to
supply all information reasonably requested by any such Inspector, Underwriter,
attorney or accountant in connection with a Shelf Registration Statement; provided that if any such information is identified by either of the Issuers or
any Guarantor as being confidential or proprietary, each Person receiving such
information shall take such actions as are reasonably necessary to protect the
confidentiality of such information to the extent such action is otherwise not
inconsistent with, an impairment of or in derogation of the rights and
interests of any Inspector, Holder or Underwriter);


 


(xiv)        in the case of a Shelf
Registration, use their reasonable best efforts to cause all Registrable
Securities to be listed on any securities exchange or any automated quotation
system on which similar securities issued or guaranteed by either of the
Issuers or any Guarantor are then listed if requested by the Majority Holders,
to the extent such Registrable Securities satisfy applicable listing
requirements;


 


(xv)         if reasonably requested
by any Holder of Registrable Securities covered by a Shelf Registration Statement,
promptly include in a Prospectus supplement or post-effective amendment such
information with respect to such Holder as such Holder reasonably requests to
be included therein and make all required filings of such Prospectus supplement
or such post-effective amendment as soon as the Issuers have received
notification of the matters to be so included in such filing; and


 


(xvi)        in the case of a Shelf
Registration, enter into such customary agreements and take all such other
actions in connection therewith (including those requested by the Holders of a
majority in principal amount of the Registrable Securities being sold) in order
to expedite or facilitate the disposition of such Registrable Securities
including, but not limited to, an Underwritten Offering and in such connection,
(1) to the extent possible, make such representations and warranties to
the Holders and any Underwriters of such Registrable Securities with respect to
the business of the Issuers and their subsidiaries and the Registration Statement,
Prospectus and documents incorporated by reference or deemed incorporated by
reference, if any, in each case, in form, substance and scope as are
customarily made by issuers to underwriters in underwritten offerings and
confirm the same if and when requested, (2) obtain opinions of counsel to
the Issuers and the Guarantors (which counsel and opinions, in form, scope and
substance, shall be reasonably satisfactory to the Holders and such
Underwriters and their respective counsel) addressed to each selling Holder and
Underwriter of Registrable Securities, covering the matters customarily covered
in opinions requested in underwritten offerings, (3) obtain “comfort”
letters from the independent registered public accounting firm of the Issuers
and the Guarantors (and, if necessary, any other independent registered public
accounting firm of any subsidiary of either of the Issuers or any Guarantor, or
of any business acquired by either of the Issuers or any Guarantor for which
financial statements and financial data are or are required to be included in
the Registration Statement) addressed to each selling Holder and Underwriter of
Registrable Securities, such letters to be in customary form and covering
matters of the type customarily covered in “comfort” letters in connection with
underwritten offerings and (4) deliver such documents and certificates as
may be reasonably requested by the Holders of a majority in principal 


 


12

















 


amount of the Registrable Securities being sold or the Underwriters,
and which are customarily delivered in underwritten offerings, to evidence the
continued validity of the representations and warranties of the Issuers and the
Guarantors made pursuant to clause (1) above and to evidence compliance
with any customary conditions contained in an underwriting agreement.


 


(b)           The Issuers shall not,
without the prior consent of the Initial Purchasers (such consent not to be
unreasonably withheld), make any offer relating to the Securities that would
reasonably be expected to constitute a “free writing prospectus,” as defined in
Rule 405 under the Securities Act.


 


(c)           In the case of a Shelf
Registration Statement, the Issuers may require each Holder of Registrable
Securities to furnish to the Issuers such information regarding such Holder and
the proposed disposition by such Holder of such Registrable Securities as the
Issuers and the Guarantors may from time to time reasonably request in writing.


 


(d)           In the case of a Shelf
Registration Statement, each Holder of Registrable Securities agrees that, upon
receipt of any notice from the Issuers and the Guarantors of the happening of
any event of the kind described in Section 3(a)(v)(3) or 3(a)(v)(5) hereof,
such Holder will forthwith discontinue disposition of Registrable Securities
pursuant to the Shelf Registration Statement until such Holder’s receipt of the
copies of the supplemented or amended Prospectus contemplated by Section 3(a)(ix) hereof
and, if so directed by the Issuers and the Guarantors, such Holder will deliver
to the Issuers and the Guarantors all copies in its possession, other than
permanent file copies then in such Holder’s possession, of the Prospectus
covering such Registrable Securities that is current at the time of receipt of
such notice.


 


(e)           If the Issuers and the
Guarantors shall give any notice pursuant to Section 3(d) hereof to
suspend the disposition of Registrable Securities pursuant to a Shelf
Registration Statement, the Issuers and the Guarantors shall extend the period
during which such Shelf Registration Statement shall be maintained effective
pursuant to this Agreement by the number of days during the period from and
including the date of the giving of such notice to and including the date when
the Holders of such Registrable Securities shall have received copies of the
supplemented or amended Prospectus necessary to resume such dispositions.  Any such suspensions shall not, in the
aggregate, exceed 90 days during any 365-day period.


 


(f)            The Holders of
Registrable Securities covered by a Shelf Registration Statement who desire to
do so may sell such Registrable Securities in an Underwritten Offering.  In any such Underwritten Offering, the
investment bank or investment banks and manager or managers (each an “Underwriter”)
that will administer the offering will be selected by the Holders of a majority
in principal amount of the Registrable Securities included in such offering.


 


4.             Participation of
Broker-Dealers in Exchange Offer.  (a) 
The Staff has taken the position that any broker-dealer that receives Exchange
Securities for its own 


 


13

















 


account in the Exchange Offer in exchange for Securities that were
acquired by such broker-dealer as a result of market-making or other trading
activities (a “Participating Broker-Dealer”) may be deemed to be an “underwriter”
within the meaning of the Securities Act and must deliver a prospectus meeting
the requirements of the Securities Act in connection with any resale of such
Exchange Securities.


 


The Issuers and the
Guarantors understand that it is the Staff’s position that if the Prospectus
contained in the Exchange Offer Registration Statement includes a plan of
distribution containing a statement to the above effect and the means by which
Participating Broker-Dealers may resell the Exchange Securities, without naming
the Participating Broker-Dealers or specifying the amount of Exchange
Securities owned by them, such Prospectus may be delivered by Participating
Broker-Dealers to satisfy their prospectus delivery obligation under the
Securities Act in connection with resales of Exchange Securities for their own
accounts, so long as the Prospectus otherwise meets the requirements of the
Securities Act.


 


(b)           In light of the above,
and notwithstanding the other provisions of this Agreement, the Issuers and the
Guarantors agree to amend or supplement the Prospectus contained in the
Exchange Offer Registration Statement for a period of up to 180 days after the
last Exchange Date (as such period may be extended pursuant to Section 3(e) of
this Agreement), if requested by the Initial Purchasers or by one or more
Participating Broker-Dealers, in order to expedite or facilitate the
disposition of any Exchange Securities by Participating Broker-Dealers
consistent with the positions of the Staff recited in Section 4(a) above.  The Issuers and the Guarantors further agree
that Participating Broker-Dealers shall be authorized to deliver such
Prospectus during such period in connection with the resales contemplated by
this Section 4.


 


(c)           The Initial Purchasers
shall have no liability to either of the Issuers, any Guarantor or any Holder
with respect to any request that they may make pursuant to Section 4(b) above.


 


5.             Indemnification
and Contribution.  (a)  Each
Issuer and each Guarantor, jointly and severally, agree to indemnify and hold
harmless each Initial Purchaser and each Holder, their respective affiliates,
directors and officers and each Person, if any, who controls any Initial
Purchaser or any Holder within the meaning of Section 15 of the Securities
Act or Section 20 of the Exchange Act, from and against any and all
losses, claims, damages and liabilities (including, without limitation, legal
fees and other expenses incurred in connection with any suit, action or
proceeding or any claim asserted, as such fees and expenses are incurred), that
arise out of, or are based upon, any untrue statement or alleged untrue
statement of a material fact contained in any Registration Statement, any
Prospectus or any “issuer free writing prospectus,” as defined in Rule 433
under the Securities Act (“Issuer FWP”), or any omission or alleged
omission to state therein a material fact required to be stated therein or
necessary in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading, except insofar as
such losses, claims, damages or liabilities arise out of, or are based upon,
any untrue statement or omission or alleged untrue statement or omission made in
reliance upon and in conformity with any information relating to any Initial 


 


14

















 


Purchaser or information relating to any Holder furnished to the
Issuers in writing by or on behalf of such Initial Purchaser or selling Holder
expressly for use therein.  In connection
with any Underwritten Offering permitted by Section 3, the Issuers and the
Guarantors, jointly and severally, will also indemnify the Underwriters, if
any, selling brokers, dealers and similar securities industry professionals
participating in the distribution, their respective affiliates and each Person
who controls such Persons (within the meaning of the Securities Act and the
Exchange Act) to the same extent as provided above with respect to the
indemnification of the Holders, if requested in connection with any
Registration Statement.


 


(b)           Each Holder agrees,
severally and not jointly, to indemnify and hold harmless the Issuers, the
Guarantors, the Initial Purchasers and the other selling Holders, the directors
of the Issuers and the Guarantors, each officer of the Issuers and the
Guarantors who signed the Registration Statement and each Person, if any, who
controls the Issuers, the Guarantors, any Initial Purchaser and any other
selling Holder within the meaning of Section 15 of the Securities Act or Section 20
of the Exchange Act to the same extent as the indemnity set forth in paragraph (a) above,
but only with respect to any losses, claims, damages or liabilities that arise
out of, or are based upon, any untrue statement or omission or alleged untrue
statement or omission made in reliance upon and in conformity with any
information relating to such Holder furnished to the Issuers in writing by such
Holder expressly for use in any Registration Statement, any Prospectus and any
Issuer FWP.


 


(c)           If any suit, action,
proceeding (including any governmental or regulatory investigation), claim or
demand shall be brought or asserted against any Person in respect of which
indemnification may be sought pursuant to either paragraph (a) or (b) above,
such Person (the “Indemnified Person”) shall promptly notify the Person
against whom such indemnification may be sought (the “Indemnifying Person”)
in writing; provided that the failure to notify the Indemnifying Person
shall not relieve it from any liability that it may have under this Section 5
except to the extent that it has been materially prejudiced (through the
forfeiture of substantive rights or defenses) by such failure; and provided,
further, that the failure to notify the Indemnifying Person shall not
relieve it from any liability that it may have to an Indemnified Person
otherwise than under this Section 5. 
If any such proceeding shall be brought or asserted against an
Indemnified Person and it shall have notified the Indemnifying Person thereof,
the Indemnifying Person shall retain counsel reasonably satisfactory to the
Indemnified Person to represent the Indemnified Person and any others entitled
to indemnification pursuant to this Section 5 that the Indemnifying Person
may designate in such proceeding and shall pay the fees and expenses of such
counsel related to such proceeding, as incurred.  In any such proceeding, any Indemnified
Person shall have the right to retain its own counsel, but the fees and
expenses of such counsel shall be at the expense of such Indemnified Person
unless (i) the Indemnifying Person and the Indemnified Person shall have
mutually agreed to the contrary; (ii) the Indemnifying Person has failed
within a reasonable time to retain counsel reasonably satisfactory to the
Indemnified Person; (iii) the Indemnified Person shall have reasonably
concluded that there may be legal defenses available to it that are different
from or in addition to those available to the Indemnifying Person; or (iv) 


 


15

















 


the named parties in any
such proceeding (including any impleaded parties) include both the Indemnifying
Person and the Indemnified Person and representation of both parties by the
same counsel would be inappropriate due to actual or potential differing
interests between them.  It is understood
and agreed that the Indemnifying Person shall not, in connection with any
proceeding or related proceeding in the same jurisdiction, be liable for the
fees and expenses of more than one separate firm (in addition to any local
counsel) for all Indemnified Persons, and that all such fees and expenses shall
be reimbursed as they are incurred.  Any
such separate firm (x) for any Initial Purchaser, its affiliates,
directors and officers and any control Persons of such Initial Purchaser shall
be designated in writing by J.P. Morgan Securities Inc., (y) for any
Holder, its directors and officers and any control Persons of such Holder shall
be designated in writing by the Majority Holders and (z) in all other
cases shall be designated in writing by the Issuers.  The Indemnifying Person shall not be liable
for any settlement of any proceeding effected without its written consent, but
if settled with such consent or if there be a final judgment for the plaintiff,
the Indemnifying Person agrees to indemnify each Indemnified Person from and
against any loss or liability by reason of such settlement or judgment.  Notwithstanding the foregoing sentence, if at
any time an Indemnified Person shall have requested that an Indemnifying Person
reimburse the Indemnified Person for fees and expenses of counsel as
contemplated by this paragraph, the Indemnifying Person shall be liable for any
settlement of any proceeding effected without its written consent if (i) such
settlement is entered into more than 30 days after receipt by the Indemnifying
Person of such request and (ii) the Indemnifying Person shall not have
reimbursed the Indemnified Person in accordance with such request prior to the
date of such settlement.  No Indemnifying
Person shall, without the written consent of the Indemnified Person, effect any
settlement of any pending or threatened proceeding in respect of which any Indemnified
Person is or could have been a party and indemnification could have been sought
hereunder by such Indemnified Person, unless such settlement (A) includes
an unconditional release of such Indemnified Person, in form and substance
reasonably satisfactory to such Indemnified Person, from all liability on
claims that are the subject matter of such proceeding and (B) does not
include any statement as to or any admission of fault, culpability or a failure
to act by or on behalf of any Indemnified Person.


 


(d)           If the indemnification
provided for in paragraphs (a) and (b) above is unavailable to an
Indemnified Person or insufficient in respect of any losses, claims, damages or
liabilities referred to therein, then each Indemnifying Person under such
paragraph, in lieu of indemnifying such Indemnified Person thereunder, shall
contribute to the amount paid or payable by such Indemnified Person as a result
of such losses, claims, damages or liabilities (i) in such proportion as
is appropriate to reflect the relative benefits received by the Issuers and the
Guarantors from the offering of the Securities and the Exchange Securities, on
the one hand, and by the Holders from receiving Securities or Exchange
Securities registered under the Securities Act, on the other hand, or (ii) if
the allocation provided by clause (i) is not permitted by applicable law,
in such proportion as is appropriate to reflect not only the relative benefits
referred to in clause (i) but also the relative fault of the Issuers and
the Guarantors on the one hand and the Holders on the other in connection with
the statements or omissions that resulted in such losses, claims, damages or
liabilities, as well as any other relevant equitable considerations.  The relative 


 


16

















 


fault of the Issuers and
the Guarantors on the one hand and the Holders on the other shall be determined
by reference to, among other things, whether the untrue or alleged untrue
statement of a material fact or the omission or alleged omission to state a
material fact relates to information supplied by the Issuers and the Guarantors
or by the Holders, and the parties’ relative intent, knowledge, access to
information and opportunity to correct or prevent such statement or omission.


 


(e)           The
Issuers, the Guarantors and the Holders agree that it would not be just and
equitable if contribution pursuant to this Section 5 were determined by pro
rata allocation (even if the Holders were treated as one entity for such
purpose) or by any other method of allocation that does not take account of the
equitable considerations referred to in paragraph (d) above.  The amount paid or payable by an Indemnified
Person as a result of the losses, claims, damages and liabilities referred to
in paragraph (d) above shall be deemed to include, subject to the
limitations set forth above, any legal or other expenses incurred by such
Indemnified Person in connection with any such action or claim.  Notwithstanding the provisions of this Section 5,
in no event shall a Holder be required to contribute any amount in excess of
the amount by which the total price at which the Securities or Exchange
Securities sold by such Holder exceeds the amount of any damages that such
Holder has otherwise been required to pay by reason of such untrue or alleged
untrue statement or omission or alleged omission.  No Person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the
Securities Act) shall be entitled to contribution from any Person who was not
guilty of such fraudulent misrepresentation.


 


(f)            The remedies provided
for in this Section 5 are not exclusive and shall not limit any rights or
remedies that may otherwise be available to any Indemnified Person at law or in
equity.


 


(g)           The indemnity and
contribution provisions contained in this Section 5 shall remain operative
and in full force and effect regardless of (i) any termination of this
Agreement, (ii) any investigation made by or on behalf of the Initial
Purchasers or any Holder or any Person controlling any Initial Purchaser or any
Holder, or by or on behalf of the Issuers or the Guarantors or the officers or
directors of or any Person controlling the Issuers or the Guarantors, (iii) acceptance
of any of the Exchange Securities and (iv) any sale of Registrable
Securities pursuant to a Shelf Registration Statement.


 


6.             General.


 


(a)           No
Inconsistent Agreements.   The Issuers and the Guarantors represent,
warrant and agree that (i) the rights granted to the Holders hereunder do
not in any way conflict with and are not inconsistent with the rights granted
to the holders of any other outstanding securities issued or guaranteed by
either of the Issuers or any Guarantor under any other agreement and (ii) neither
the Issuers nor any Guarantor has entered into, or on or after the date of this
Agreement will enter into, any agreement that is inconsistent with the rights
granted to the Holders of Registrable Securities in this Agreement or otherwise
conflicts with the provisions hereof.


 


17

















 


(b)           Amendments
and Waivers.   The provisions of this Agreement, including
the provisions of this sentence, may not be amended, modified or supplemented,
and waivers or consents to departures from the provisions hereof may not be
given unless the Issuers and the Guarantors have obtained the written consent
of Holders of at least a majority in aggregate principal amount of the
outstanding Registrable Securities affected by such amendment, modification,
supplement, waiver or consent; provided that no amendment, modification,
supplement, waiver or consent to any departure from the provisions of Section 5
hereof shall be effective as against any Holder of Registrable Securities
unless consented to in writing by such Holder. 
Any amendments, modifications, supplements, waivers or consents pursuant
to this Section 6(b) shall be by a writing executed by each of the
parties hereto.


 


(c)           Notices.  All notices and other communications provided
for or permitted hereunder shall be made in writing by hand-delivery,
registered first-class mail, telecopier, or any courier guaranteeing overnight
delivery (i) if to a Holder, at the most current address given by such
Holder to the Issuers by means of a notice given in accordance with the
provisions of this Section 6(c), which address initially is, with respect
to the Initial Purchasers, the address set forth in the Purchase Agreement; (ii) if
to the Issuers and the Guarantors, initially at the Issuers’ address set forth
in the Purchase Agreement and thereafter at such other address, notice of which
is given in accordance with the provisions of this Section 6(c); and (iii) to
such other persons at their respective addresses as provided in the Purchase
Agreement and thereafter at such other address, notice of which is given in
accordance with the provisions of this Section 6(c).  All such notices and communications shall be
deemed to have been duly given: at the time delivered by hand, if personally
delivered; five Business Days after being deposited in the mail, postage
prepaid, if mailed; when receipt is acknowledged, if telecopied; and on the
next Business Day if timely delivered to an air courier guaranteeing overnight
delivery.  Copies of all such notices,
demands or other communications shall be concurrently delivered by the Person
giving the same to the Trustee, at the address specified in the Indenture.


 


(d)           Successors
and Assigns. This Agreement shall inure to the benefit of and be
binding upon the successors, assigns and transferees of each of the parties,
including, without limitation and without the need for an express assignment,
subsequent Holders; provided that nothing herein shall be deemed to
permit any assignment, transfer or other disposition of Registrable Securities
in violation of the terms of the Purchase Agreement or the Indenture.  If any transferee of any Holder shall acquire
Registrable Securities in any manner, whether by operation of law or otherwise,
such Registrable Securities shall be held subject to all the terms of this Agreement,
and by taking and holding such Registrable Securities such Person shall be
conclusively deemed to have agreed to be bound by and to perform all of the
terms and provisions of this Agreement and such Person shall be entitled to
receive the benefits hereof.  The Initial
Purchasers (in their capacity as Initial Purchasers) shall have no liability or
obligation to the Issuers or the Guarantors with respect to any failure by a
Holder to comply with, or any breach by any Holder of, any of the obligations
of such Holder under this Agreement.


 


18

















 


(e)           Third Party
Beneficiaries.  Each Holder
shall be a third party beneficiary to the agreements made between the Issuers
and the Guarantors, on the one hand, and the Initial Purchasers, on the other
hand, and shall have the right to enforce such agreements directly to the
extent it deems such enforcement necessary or advisable to protect its rights
or the rights of other Holders hereunder.


 


(f)            Counterparts.
This Agreement may be executed in any number of counterparts and by the parties
hereto in separate counterparts, each of which when so executed shall be deemed
to be an original and all of which taken together shall constitute one and the
same agreement.


 


(g)           Headings.  The headings in this Agreement are
for convenience of reference only, are not a part of this Agreement and shall
not limit or otherwise affect the meaning hereof.


 


(h)           Governing
Law.  This Agreement shall be
governed by and construed in accordance
with the laws of the State of New York.


 


(j)            Miscellaneous.  This
Agreement contains the entire agreement between the parties relating to the
subject matter hereof and supersedes all oral statements and prior writings
with respect thereto.  If any term,
provision, covenant or restriction contained in this Agreement is held by a
court of competent jurisdiction to be invalid, void or unenforceable or against
public policy, the remainder of the terms, provisions, covenants and
restrictions contained herein shall remain in full force and effect and shall
in no way be affected, impaired or invalidated. 
The Issuers, the Guarantors and the Initial Purchasers shall endeavor in
good faith negotiations to replace the invalid, void or unenforceable
provisions with valid provisions the economic effect of which comes as
close as possible to that of the invalid, void or unenforceable provisions.


 


19
















 


IN
WITNESS WHEREOF, the parties have executed this Agreement as of the date first
written above.


 


	
   

  	
   

  	
  Issuers:

  	
   

  
	
   

  	
   

  	
  MARKWEST
  ENERGY FINANCE CORPORATION

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  ENERGY PARTNERS, L.P.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  General Partner

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  



 


[Registration Rights Agreement]


 

















 


	
   

  	
   

  	
  Subsidiary
  Guarantors:

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  HYDROCARBON, INC.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  ENERGY GP, L.L.C.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MASON
  PIPELINE LIMITED LIABILITY COMPANY

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Hydrocarbon, Inc.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  Sole Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  
						



 


[Registration Rights Agreement]


 

















 


	
   

  	
   

  	
  MARKWEST
  ENERGY OPERATING COMPANY, L.L.C.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Partners, L.P.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  General Partner

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  BASIN
  PIPELINE L.L.C. 

  
	
   

  	
   

  	
  WEST
  SHORE PROCESSING COMPANY, L.L.C.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Operating Company, L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  Sole Member and Manager

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Partners, L.P.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its
  General Partner

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  



 


[Registration Rights Agreement]


 

















 


	
   

  	
  MARKWEST BLACKHAWK, L.L.C.

  
	
   

  	
  MARKWEST ENERGY APPALACHIA, L.L.C.

  
	
   

  	
  MARKWEST
  ENERGY EAST TEXAS GAS COMPANY, L.L.C.

  
	
   

  	
  MARKWEST GAS MARKETING, L.L.C.

  
	
   

  	
  MARKWEST GAS SERVICES, L.L.C.

  
	
   

  	
  MARKWEST JAVELINA COMPANY, L.L.C.

  
	
   

  	
  MARKWEST JAVELINA PIPELINE COMPANY, L.L.C.

  
	
   

  	
  MARKWEST LIBERTY GAS GATHERING, L.L.C.

  
	
   

  	
  MARKWEST MARKETING, L.L.C.

  
	
   

  	
  MARKWEST NEW MEXICO, L.L.C.

  
	
   

  	
  MARKWEST PINNACLE, L.L.C.

  
	
   

  	
  MARKWEST PIONEER, L.L.C.

  
	
   

  	
  MARKWEST PIPELINE COMPANY, L.L.C.

  
	
   

  	
  MARKWEST PNG UTILITY, L.L.C.

  
	
   

  	
  MARKWEST POWER TEX, L.L.C.

  
	
   

  	
  MARKWEST TEXAS PNG UTILITY, L.L.C.

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest Energy Operating Company, L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its Sole Member

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest Energy Partners, L.P.,

  
	
   

  	
   

  	
   

  	
   

  	
  its Managing Member

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MarkWest Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its General Partner

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  



 


[Registration Rights Agreement]


 

















 


	
   

  	
  MARKWEST MICHIGAN PIPELINE COMPANY, L.L.C.

  
	
   

  	
  MARKWEST OKLAHOMA GAS COMPANY, L.L.C.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Operating Company, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Partners, L.P.,

  
	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  General Partner

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  



 


[Registration Rights Agreement]


 

















 


	
   

  	
  MATREX,
  L.L.C.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  Basin
  Pipeline L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  Sole Member and Manager

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Operating Company, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  Sole Member and Manager

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Partners, L.P.,

  
	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  General Partner

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  MCALESTER, L.L.C.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Oklahoma Gas Company, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  Sole Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Operating Company, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy Partners, L.P.,

  
	
   

  	
   

  	
   

  	
  its
  Managing Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest
  Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its
  General Partner

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/
  Nancy K. Buese

  
	
   

  	
  Name:

  	
  Nancy
  Buese

  
	
   

  	
  Title:

  	
  Senior
  Vice President and Chief Financial Officer

  



 


[Registration Rights Agreement]


 

















 


Confirmed and accepted as
of the date first above written:


 


J.P.
MORGAN SECURITIES INC.


RBC
CAPITAL MARKETS, LLC


WACHOVIA
CAPITAL MARKETS, LLC


BARCLAYS
CAPITAL INC.


DEUTSCHE
BANK SECURITIES INC.


U.S.
BANCORP INVESTMENTS, INC.


 


 


By:  J.P. MORGAN SECURITIES INC.


 


	
  By:

  	
  /s/
  Lawrence S. Landry

  	
   

  
	
   

  	
  Name:
  Lawrence S. Landry

  
	
   

  	
  Title:
  Managing Director

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:
  RBC CAPITAL MARKETS, LLC

  
	
   

  	
   

  
	
  By:

  	
  /s/
  Nicholas Daisotis

  	
   

  
	
   

  	
  Name:
  Nicholas Daisotis

  
	
   

  	
  Title:
  Managing Director

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:

  	
  WACHOVIA
  CAPITAL MARKETS, LLC

  
	
   

  	
   

  
	
  By:

  	
  /s/
  Todd Schanzlin

  	
   

  
	
   

  	
  Name:
  Todd Schanzlin

  
	
   

  	
  Title:
  Director

  



 


Signature Page to Registration
Rights Agreement