Document:

Exhibit 4.1

 

 

 

MARKWEST ENERGY PARTNERS, L.P.,

 

MARKWEST ENERGY FINANCE CORPORATION, as
Issuers,

 

THE SUBSIDIARIES NAMED HEREIN, as Subsidiary
Guarantors

 

AND

 

WELLS FARGO BANK, NATIONAL ASSOCIATION, as
Trustee

	
   

  	
   

  	
   

  	
   

  	
   

  

 

83⁄4% Series A Senior Notes due 2018

 

83⁄4% Series B Senior Notes due 2018

	
   

  	
   

  	
   

  	
   

  	
   

  

 

INDENTURE

 

Dated as of April 15, 2008

 

 

 

 

CROSS-REFERENCE TABLE*

 

	
  Trust Indenture

  	
   

  	
  Indenture

  
	
  Act Section

  	
   

  	
  Section(s)

  
	
  310

  	
   

  	
  (a)(1)

  	
   

  	
  7.10

  
	
   

  	
   

  	
  (a)(2)

  	
   

  	
  7.10

  
	
   

  	
   

  	
  (a)(3)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (a)(4)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (a)(5)

  	
   

  	
  7.10

  
	
   

  	
   

  	
  (b)

  	
   

  	
  7.10

  
	
   

  	
   

  	
  (c)

  	
   

  	
  N.A.

  
	
  311

  	
   

  	
  (a)

  	
   

  	
  7.11

  
	
   

  	
   

  	
  (b)

  	
   

  	
  7.11

  
	
   

  	
   

  	
  (c)

  	
   

  	
  N.A.

  
	
  312

  	
   

  	
  (a)

  	
   

  	
  2.05

  
	
   

  	
   

  	
  (b)

  	
   

  	
  12.03

  
	
   

  	
   

  	
  (c)

  	
   

  	
  12.03

  
	
  313

  	
   

  	
  (a)

  	
   

  	
  7.06

  
	
   

  	
   

  	
  (b)(1)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (b)(2)

  	
   

  	
  7.06

  
	
   

  	
   

  	
  (c)

  	
   

  	
  7.06; 12.02

  
	
   

  	
   

  	
  (d)

  	
   

  	
  7.06

  
	
  314

  	
   

  	
  (a)

  	
   

  	
  4.03; 4.18; 12.02

  
	
   

  	
   

  	
  (b)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (c)(1)

  	
   

  	
  12.04

  
	
   

  	
   

  	
  (c)(2)

  	
   

  	
  12.04

  
	
   

  	
   

  	
  (c)(3)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (d)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (e)

  	
   

  	
  12.05

  
	
   

  	
   

  	
  (f)

  	
   

  	
  N.A.

  
	
  315

  	
   

  	
  (a)

  	
   

  	
  7.01

  
	
   

  	
   

  	
  (b)

  	
   

  	
  7.05; 12.02

  
	
   

  	
   

  	
  (c)

  	
   

  	
  7.01

  
	
   

  	
   

  	
  (d)

  	
   

  	
  7.01; 6.05

  
	
   

  	
   

  	
  (e)

  	
   

  	
  6.11

  
	
  316

  	
   

  	
  (a)(last sentence)

  	
   

  	
  2.09

  
	
   

  	
   

  	
  (a)(1)(A)

  	
   

  	
  6.05

  
	
   

  	
   

  	
  (a)(1)(B)

  	
   

  	
  6.04

  
	
   

  	
   

  	
  (a)(2)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (b)

  	
   

  	
  6.07

  
	
   

  	
   

  	
  (c)

  	
   

  	
  9.04

  
	
  317

  	
   

  	
  (a)(1)

  	
   

  	
  6.08

  
	
   

  	
   

  	
  (a)(2)

  	
   

  	
  6.09

  
	
   

  	
   

  	
  (b)

  	
   

  	
  2.04

  
	
  318

  	
   

  	
  (a)

  	
   

  	
  12.01

  
	
   

  	
   

  	
  (b)

  	
   

  	
  N.A.

  
	
   

  	
   

  	
  (c)

  	
   

  	
  12.01

  

 

N.A. means not applicable.

*This Cross-Reference Table is not part of
the Indenture.

 

 

TABLE OF CONTENTS

 

	
   

  	
  Page

  
	
   

  	
   

  
	
  ARTICLE 1
  DEFINITIONS AND INCORPORATION BY REFERENCE

  	
  1

  
	
   

  	
  Section 1.01.

  	
  Definitions

  	
  1

  
	
   

  	
  Section 1.02.

  	
  Other Definitions

  	
  27

  
	
   

  	
  Section 1.03.

  	
  Incorporation by Reference of Trust
  Indenture Act

  	
  27

  
	
   

  	
  Section 1.04.

  	
  Rules of Construction

  	
  28

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 2 THE NOTES

  	
  28

  
	
   

  	
  Section 2.01.

  	
  Form and Dating

  	
  28

  
	
   

  	
  Section 2.02.

  	
  Execution and Authentication

  	
  29

  
	
   

  	
  Section 2.03.

  	
  Registrar and Paying Agent

  	
  30

  
	
   

  	
  Section 2.04.

  	
  Paying Agent to Hold Money in Trust

  	
  30

  
	
   

  	
  Section 2.05.

  	
  Holder Lists

  	
  30

  
	
   

  	
  Section 2.06.

  	
  Transfer and Exchange

  	
  31

  
	
   

  	
  Section 2.07.

  	
  Replacement Notes

  	
  40

  
	
   

  	
  Section 2.08.

  	
  Outstanding Notes

  	
  40

  
	
   

  	
  Section 2.09.

  	
  Treasury Notes

  	
  40

  
	
   

  	
  Section 2.10.

  	
  Temporary Notes

  	
  41

  
	
   

  	
  Section 2.11.

  	
  Cancellation

  	
  41

  
	
   

  	
  Section 2.12.

  	
  Defaulted Interest

  	
  41

  
	
   

  	
  Section 2.13.

  	
  CUSIP Numbers

  	
  41

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 3
  REDEMPTION AND PREPAYMENT

  	
  42

  
	
   

  	
  Section 3.01.

  	
  Notices to Trustee

  	
  42

  
	
   

  	
  Section 3.02.

  	
  Selection of Notes to Be Redeemed

  	
  42

  
	
   

  	
  Section 3.03.

  	
  Notice of Redemption

  	
  42

  
	
   

  	
  Section 3.04.

  	
  Effect of Notice of Redemption

  	
  43

  
	
   

  	
  Section 3.05.

  	
  Deposit of Redemption Price

  	
  44

  
	
   

  	
  Section 3.06.

  	
  Notes Redeemed in Part

  	
  44

  
	
   

  	
  Section 3.07.

  	
  Optional Redemption

  	
  44

  
	
   

  	
  Section 3.08.

  	
  Mandatory Redemption

  	
  45

  
	
   

  	
  Section 3.09.

  	
  Offer to Purchase by Application of Net
  Proceeds

  	
  45

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 4 COVENANTS

  	
  47

  
	
   

  	
  Section 4.01.

  	
  Payment of Notes

  	
  47

  
	
   

  	
  Section 4.02.

  	
  Maintenance of Office or Agency

  	
  48

  
	
   

  	
  Section 4.03.

  	
  Compliance Certificate

  	
  48

  
	
   

  	
  Section 4.04.

  	
  Taxes

  	
  49

  
	
   

  	
  Section 4.05.

  	
  Stay, Extension and Usury Laws

  	
  49

  
	
   

  	
  Section 4.06.

  	
  Change of Control

  	
  49

  
	
   

  	
  Section 4.07.

  	
  Asset Sales

  	
  51

  
	
   

  	
  Section 4.08.

  	
  Restricted Payments

  	
  53

  
	
   

  	
  Section 4.09.

  	
  Incurrence of Indebtedness and Issuance of
  Disqualified Equity

  	
  56

  
	
   

  	
  Section 4.10.

  	
  Liens

  	
  59

  
	
   

  	
  Section 4.11.

  	
  Dividend and Other Payment Restrictions
  Affecting Subsidiaries

  	
  59

  

 

i

 

	
   

  	
  Page

  
	
   

  	
   

  
	
   

  	
  Section 4.12.

  	
  Transactions With Affiliates

  	
  60

  
	
   

  	
  Section 4.13.

  	
  Additional Subsidiary Guarantees

  	
  61

  
	
   

  	
  Section 4.14.

  	
  Designation of Restricted and Unrestricted
  Subsidiaries

  	
  62

  
	
   

  	
  Section 4.15.

  	
  Business Activities

  	
  62

  
	
   

  	
  Section 4.16.

  	
  Sale and Leaseback Transactions

  	
  63

  
	
   

  	
  Section 4.17.

  	
  Payments for Consent

  	
  63

  
	
   

  	
  Section 4.18.

  	
  Reports

  	
  63

  
	
   

  	
  Section 4.19.

  	
  Termination of Covenants

  	
  64

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 5
  SUCCESSORS

  	
  64

  
	
   

  	
  Section 5.01.

  	
  Merger, Consolidation, or Sale of Assets

  	
  64

  
	
   

  	
  Section 5.02.

  	
  Successor Entity Substituted

  	
  66

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 6 DEFAULTS
  AND REMEDIES

  	
  67

  
	
   

  	
  Section 6.01.

  	
  Events of Default

  	
  67

  
	
   

  	
  Section 6.02.

  	
  Acceleration

  	
  69

  
	
   

  	
  Section 6.03.

  	
  Other Remedies

  	
  70

  
	
   

  	
  Section 6.04.

  	
  Waiver of Past Defaults

  	
  70

  
	
   

  	
  Section 6.05.

  	
  Control by Majority

  	
  70

  
	
   

  	
  Section 6.06.

  	
  Limitation on Suits

  	
  71

  
	
   

  	
  Section 6.07.

  	
  Rights of Holders of Notes to Receive
  Payment

  	
  71

  
	
   

  	
  Section 6.08.

  	
  Collection Suit by Trustee

  	
  71

  
	
   

  	
  Section 6.09.

  	
  Trustee May File Proofs of Claim

  	
  71

  
	
   

  	
  Section 6.10.

  	
  Priorities

  	
  72

  
	
   

  	
  Section 6.11.

  	
  Undertaking for Costs

  	
  72

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 7 TRUSTEE

  	
  73

  
	
   

  	
  Section 7.01.

  	
  Duties of Trustee

  	
  73

  
	
   

  	
  Section 7.02.

  	
  Rights of Trustee

  	
  74

  
	
   

  	
  Section 7.03.

  	
  Individual Rights of Trustee

  	
  76

  
	
   

  	
  Section 7.04.

  	
  Trustee’s Disclaimer

  	
  76

  
	
   

  	
  Section 7.05.

  	
  Notice of Defaults

  	
  76

  
	
   

  	
  Section 7.06.

  	
  Reports by Trustee to Holders of the Notes

  	
  76

  
	
   

  	
  Section 7.07.

  	
  Compensation and Indemnity

  	
  77

  
	
   

  	
  Section 7.08.

  	
  Replacement of Trustee

  	
  78

  
	
   

  	
  Section 7.09.

  	
  Successor Trustee by Merger, Etc.

  	
  79

  
	
   

  	
  Section 7.10.

  	
  Eligibility; Disqualification

  	
  79

  
	
   

  	
  Section 7.11.

  	
  Preferential Collection of Claims Against
  Issuers

  	
  79

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 8 LEGAL
  DEFEASANCE AND COVENANT DEFEASANCE

  	
  79

  
	
   

  	
  Section 8.01.

  	
  Option to Effect Legal Defeasance or
  Covenant Defeasance

  	
  79

  
	
   

  	
  Section 8.02.

  	
  Legal Defeasance and Discharge

  	
  79

  
	
   

  	
  Section 8.03.

  	
  Covenant Defeasance

  	
  80

  
	
   

  	
  Section 8.04.

  	
  Conditions to Legal Defeasance or Covenant
  Defeasance

  	
  81

  
	
   

  	
  Section 8.05.

  	
  Deposited Money and Government Securities
  to be Held in Trust, Other Miscellaneous Provisions

  	
  82

  
					

 

ii

 

	
   

  	
  Page

  
	
   

  	
   

  
	
   

  	
  Section 8.06.

  	
  [Intentionally omitted]

  	
  82

  
	
   

  	
  Section 8.07.

  	
  Reinstatement

  	
  82

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 9
  AMENDMENT, SUPPLEMENT AND WAIVER

  	
  83

  
	
   

  	
  Section 9.01.

  	
  Without Consent of Holders of Notes

  	
  83

  
	
   

  	
  Section 9.02.

  	
  With Consent of Holders of Notes

  	
  84

  
	
   

  	
  Section 9.03.

  	
  Compliance with Trust Indenture Act

  	
   

  
	
   

  	
  Section 9.04.

  	
  Revocation and Effect of Consents

  	
  85

  
	
   

  	
  Section 9.05.

  	
  Notation or Exchange of Notes

  	
  86

  
	
   

  	
  Section 9.06.

  	
  Trustee to Sign Amendments, Etc.

  	
  86

  
	
   

  	
  Section 9.07.

  	
  Effect of Supplemental Indentures

  	
  86

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 10
  GUARANTEES

  	
  87

  
	
   

  	
  Section 10.01.

  	
  Guarantees

  	
  87

  
	
   

  	
  Section 10.02.

  	
  Limitation of Guarantor’s Liability

  	
  88

  
	
   

  	
  Section 10.03.

  	
  Execution and Delivery of Notations of
  Guarantees

  	
  88

  
	
   

  	
  Section 10.04.

  	
  [Intentionally omitted]

  	
  89

  
	
   

  	
  Section 10.05.

  	
  Releases

  	
  89

  
	
   

  	
  Section 10.06.

  	
  “Trustee” to Include Paying Agent

  	
  89

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 11
  SATISFACTION AND DISCHARGE

  	
  90

  
	
   

  	
  Section 11.01.

  	
  Satisfaction and Discharge

  	
  90

  
	
   

  	
  Section 11.02.

  	
  Application of Trust

  	
  91

  
	
   

  	
  Section 11.03.

  	
  Repayment of the Issuers

  	
  91

  
	
   

  	
  Section 11.04.

  	
  Reinstatement

  	
  92

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 12
  MISCELLANEOUS

  	
  92

  
	
   

  	
  Section 12.01.

  	
  Trust Indenture Act Controls

  	
  92

  
	
   

  	
  Section 12.02.

  	
  Notices

  	
  92

  
	
   

  	
  Section 12.03.

  	
  Communication by Holders of Notes with
  Other Holders of Notes

  	
  93

  
	
   

  	
  Section 12.04.

  	
  Certificate and Opinion as to Conditions
  Precedent

  	
  93

  
	
   

  	
  Section 12.05.

  	
  Statements Required in Certificate or
  Opinion

  	
  94

  
	
   

  	
  Section 12.06.

  	
  Rules by Trustee and Agents

  	
  95

  
	
   

  	
  Section 12.07.

  	
  No Personal Liability of Directors,
  Officers, Employees and Unitholders and No Recourse Against General Partner

  	
  95

  
	
   

  	
  Section 12.08.

  	
  Governing Law

  	
  95

  
	
   

  	
  Section 12.09.

  	
  No Adverse Interpretation of Other
  Agreements

  	
  95

  
	
   

  	
  Section 12.10.

  	
  Successors

  	
  95

  
	
   

  	
  Section 12.11.

  	
  Severability

  	
  95

  
	
   

  	
  Section 12.12.

  	
  Counterpart Originals

  	
  95

  
	
   

  	
  Section 12.13.

  	
  Table of Contents, Headings, Etc.

  	
  96

  
					

 

iii

 

SCHEDULES, EXHIBITS AND ANNEXES

 

	
  SCHEDULE A

  	
   

  	
  Schedule of Subsidiary Guarantors

  	
   

  	
   

  
	
  EXHIBIT A

  	
   

  	
  Form of Note

  	
   

  	
  Exhibit A Page 1

  
	
  EXHIBIT B

  	
   

  	
  Form of Certificate of Transfer

  	
   

  	
  Exhibit B Page 1

  
	
  EXHIBIT C

  	
   

  	
  Form of Certificate of Exchange

  	
   

  	
  Exhibit C Page 1

  
	
  EXHIBIT D

  	
   

  	
  Form of Guarantee Notation

  	
   

  	
  Exhibit D Page 1

  
	
  EXHIBIT E

  	
   

  	
  Form of Certificates from Acquiring
  Institutional Accredited Investor

  	
   

  	
  Exhibit E Page 1

  
	
  ANNEX A

  	
   

  	
  Form of Supplemental Indenture

  	
   

  	
  A-1

  
	
  ANNEX B

  	
   

  	
  Form of Registration Rights Agreement

  	
   

  	
  B-1

  

 

iv

 

THIS INDENTURE
dated as of April 15, 2008 is among MarkWest Energy Partners, L.P., a
Delaware limited partnership (the “Partnership”), MarkWest Energy Finance
Corporation, a Delaware corporation (“MarkWest Finance” and, collectively with
the Partnership, the “Issuers”), the Subsidiary Guarantors (as defined herein)
listed on Schedule A hereto, and Wells Fargo Bank, National Association, a
national banking association, as trustee (the “Trustee”).

 

The Issuers,
the Subsidiary Guarantors, and the Trustee agree as follows for the benefit of
each other and for the equal and ratable benefit of the Holders of the 83⁄4% Series A
Senior Notes due 2018 (the “Series A Notes”) and the 83⁄4% Series B
Senior Notes due 2018 (the “Exchange Notes” and, together with the Series A
Notes, the “Notes”):

 

ARTICLE 1

DEFINITIONS AND INCORPORATION BY REFERENCE

 

Section 1.01.                  Definitions.

 

“144A Global Note” means the Global Note in the form of Exhibit A
hereto bearing the Global Note Legend and the Private Placement Legend and that
has the “Schedule of Exchange of Interests in the Global Note” attached thereto
and deposited with and registered in the name of the Depositary or its nominee
that will be issued in a denomination equal to the outstanding principal amount
of the Notes sold in reliance on Rule 144A, subject to adjustment as
provided in Section 2.06 hereof.

 

“Acquired Debt” means, with respect to any specified Person: (1) Indebtedness
of any other Person existing at the time such other Person is merged with or
into or became a Subsidiary of such specified Person, whether or not such
Indebtedness is incurred in connection with, or in contemplation of, such other
Person merging with or into, or becoming a Subsidiary of, such specified
Person, but excluding Indebtedness that is extinguished, retired or repaid in
connection with such Person merging with or becoming a Subsidiary of such
specified Person; and (2) Indebtedness secured by a Lien encumbering any
asset acquired by such specified Person.

 

“Additional Interest” means all additional interest then
owing pursuant to a Registration Rights Agreement.  Unless the context indicates otherwise, all
references to “interest” in this Indenture or the Notes shall be deemed to
include any Additional Interest.

 

“Affiliate” of any specified Person means any other Person
directly or indirectly controlling or controlled by or under direct or indirect
common control with such specified Person. 
For purposes of this definition, “control,” as used with respect to any
Person, shall mean the possession, directly or indirectly, of the power to
direct or cause the direction of the management or policies of such Person,
whether through the ownership of voting securities, by agreement or otherwise;
provided that beneficial ownership of 10% or more of the Voting Stock of a
specified Person shall be deemed to be control by the other Person; provided,
further, that any third Person which also beneficially owns 10% or more of the
Voting Stock of a specified Person shall not be deemed to be an Affiliate of
either the specified Person or the other Person merely because of such common
ownership in such specified Person.  For
purposes of this definition, the terms “controlling,” “controlled by” and “under
common control with” shall have 

 

1

 

correlative meanings.  Notwithstanding the preceding, the term “Affiliate”
shall not include a Restricted Subsidiary of any specified Person.

 

“Agent” means any Registrar or Paying Agent.

 

“Applicable Procedures” means, with respect to any transfer
or exchange of or for beneficial interests in any Global Note, the rules and
procedures of the Depositary, Euroclear and Clearstream that apply to such
transfer or exchange.

 

“Asset Sale”
means:

 

(1)           the sale, lease,
conveyance or other disposition of any assets, other than sales of inventory in
the ordinary course of business; provided that the sale, lease, conveyance or
other disposition of all or substantially all of the assets of the Partnership
and its Restricted Subsidiaries taken as a whole will be governed by the
provisions of Section 4.06 and/or the provisions of Article 5 hereof
and not by the provisions of Section 4.07; and

 

(2)           the issuance of
Equity Interests by any of the Partnership’s Restricted Subsidiaries or the
sale by the Partnership or any of its Restricted Subsidiaries of Equity
Interests in any of its Restricted Subsidiaries.

 

Notwithstanding the preceding, the following
items shall not be deemed to be Asset Sales:

 

(1)           any single
transaction or series of related transactions that: (a) involves assets
having a fair market value of less than $5.0 million; or (b) results in
net proceeds to the Partnership and its Restricted Subsidiaries of less than
$5.0 million;

 

(2)           a transfer of assets
between or among the Partnership and its Restricted Subsidiaries;

 

(3)           an issuance or sale
of Equity Interests by a Restricted Subsidiary to the Partnership or to another
Restricted Subsidiary of the Partnership;

 

(4)           a Restricted Payment
that is permitted under Section 4.08 hereof or a Permitted Investment;

 

(5)           the sale or other
disposition of cash or Cash Equivalents, Hedging Obligations or other financial
instruments in the ordinary course of business;

 

(6)           any trade or exchange
by the Partnership or any of its Restricted Subsidiaries of properties or
assets for properties or assets owned or held by another Person, provided that
the fair market value of the properties or assets traded or exchanged by the
Partnership or such Restricted Subsidiary (together with any cash) is
reasonably equivalent to the fair market value of the properties or assets
(together with any cash) to be received by the Partnership or such Restricted
Subsidiary, and provided further that any cash received must be applied in
accordance with the provisions of Section 4.07 hereof;

 

2

 

(7)           surrender or waiver
of contract rights or the settlement, release or surrender of contract, tort or
other claims of any kind;

 

(8)           the creation or
perfection of a Lien that is not prohibited by Section 4.10;

 

(9)           dispositions in
connection with Permitted Liens; and

 

(10)         the grant in the
ordinary course of business of any non-exclusive license of patents,
trademarks, registrations therefor and other similar intellectual property.

 

“Attributable Debt” in respect of a sale and lease-back
transaction means, at the time of determination, the present value of the
obligation of the lessee for net rental payments during the remaining term of
the lease included in such sale and lease-back transaction, including any
period for which such lease has been extended or may, at the option of the
lessor, be extended.  Such present value
shall be calculated using a discount rate equal to the rate of interest
implicit in such transaction, determined in accordance with GAAP.

 

“Available Cash” has the meaning assigned to such term in the
Partnership Agreement, as in effect on the Issue Date.

 

“Bankruptcy Law” means Title 11, U.S. Code or any similar federal
or state law for the relief of debtors.

 

“Beneficial Owner”
has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5
under the Exchange Act, except that in calculating the beneficial ownership of
any particular “person” (as that term is used in Section 13(d)(3) of
the Exchange Act), such “person” will be deemed to have beneficial ownership of
all securities that such “person” has the right to acquire by conversion or
exercise of other securities, whether such right is currently exercisable or is
exercisable only upon the occurrence of a subsequent condition.  The terms “Beneficially Owns” and “Beneficially
Owned” have correlative meanings.

 

“Board of Directors” means, with respect to the Partnership,
the Board of Directors of the General Partner, or any authorized committee of
such Board of Directors, and with respect to MarkWest Finance or any other
Subsidiary of the Partnership, the Board of Directors or managing members of
such Person.

 

“Board Resolution” means a copy of a resolution certified by
the Secretary or an Assistant Secretary of the applicable Person to have been
duly adopted by the Board of Directors of such Person and to be in full force
and effect on the date of such certification, and delivered to the Trustee.

 

“Business Day” means any day other than a Legal Holiday.

 

“Capital Lease Obligation” means, at the time any
determination thereof is to be made, the amount of the liability in respect of
a capital lease that would at that time be required to be capitalized on a
balance sheet in accordance with GAAP.

 

3

 

“Cash Equivalents” means:

 

(1)           United States
dollars or, in an amount up to the amount necessary or appropriate to fund
local operating expenses, other currencies;

 

(2)           securities issued or
directly and fully guaranteed or insured by the United States government or any
agency or instrumentality thereof (provided that the full faith and credit of
the United States is pledged in support thereof) having maturities of not more
than one year from the date of acquisition;

 

(3)           certificates of
deposit, time deposits and eurodollar time deposits with maturities of one year
or less from the date of acquisition, bankers’ acceptances with maturities not
exceeding 365 days, demand and overnight bank deposits and other similar types
of investments routinely offered by commercial banks, in each case, with any
domestic commercial bank having a combined capital and surplus in excess of
$500.0 million and a Thomson BankWatch Rating of “B” or better or any
commercial bank of any other country that is a member of the Organization for
Economic Cooperation and Development (“OECD”) and has total assets in excess of
$500.0 million;

 

(4)           repurchase
obligations with a term of not more than seven days for underlying securities
of the types described in clauses (2) and (3) above entered into with
any financial institution meeting the qualifications specified in clause (3) above;

 

(5)           commercial paper
having one of the two highest ratings obtainable from Moody’s or Standard &
Poor’s and in each case maturing within six months after the date of
acquisition; and

 

(6)           money market funds
at least 95% of the assets of which constitute Cash Equivalents of the kinds
described in clauses (1) through (5) of this definition.

 

“Certificated Note” means a certificated Note registered in
the name of the Holder thereof and issued in accordance with Section 2.06
hereof, in the form of Exhibit A hereto, except that such Note shall not
bear the Global Note Legend, shall not have the phrase identified by footnote 3
thereto and shall not have the “Schedule of Exchanges of Interests in the
Global Note” attached thereto.

 

“Change of Control” means the occurrence of any of the
following:

 

(1)           the direct or
indirect sale, lease, transfer, conveyance or other disposition (other than by
way of merger or consolidation), in one or a series of related transactions, of
all or substantially all of the properties or assets (including Equity
Interests of the Restricted Subsidiaries) of the Partnership and its Restricted
Subsidiaries taken as a whole, to any “person” (as that term is used in Section 13(d)(3) of
the Exchange Act);

 

(2)           the adoption of a
plan relating to the liquidation or dissolution of the Partnership or the
removal of the General Partner by the limited partners of the Partnership;

 

4

 

(3)           the consummation of
any transaction (including, without limitation, any merger or consolidation)
the result of which is that any “person” (as that term is used in Section 13(d)(3) of
the Exchange Act), excluding the MarkWest Hydrocarbon Group, becomes the
Beneficial Owner, directly or indirectly, of more than 50% of the Voting Stock
of the General Partner, measured by voting power rather than number of shares;

 

(4)           the consummation of
any transaction (including, without limitation, any merger or consolidation)
the result of which is that any “person” (as that term is used in Section 13(d)(3) of
the Exchange Act), excluding the Persons referred to in clause (1) of the
definition of “MarkWest Hydrocarbon Group,” becomes the Beneficial Owner,
directly or indirectly, of more than 50% of the Voting Stock of the
Partnership, measured by voting power rather than number of shares, at a time
when the Partnership still Beneficially Owns more than 50% of the Voting Stock
of the General Partner, measured by voting power rather than number of shares;
or

 

(5)           the first day on
which a majority of the members of the Board of Directors of the General
Partner are not Continuing Directors.

 

Notwithstanding the preceding, a conversion of
the Partnership from a limited partnership to a corporation, limited liability
company or other form of entity or an exchange of all of the outstanding
limited partnership interests for capital stock in a corporation, for member
interests in a limited liability company or for Equity Interests in such other
form of entity shall not constitute a Change of Control, so long as following
such conversion or exchange the MarkWest Hydrocarbon Group Beneficially Owns,
directly or indirectly, in the aggregate more than 50% of the Voting Stock of
such entity, or continues to Beneficially Own a sufficient percentage of Voting
Stock of such entity to elect a majority of its directors, managers, trustees
or other persons serving in a similar capacity for such entity.

 

“Clearstream” means Clearstream Banking, S.A. or any
successor securities clearing agency.

 

“Code” means the Internal Revenue Code of 1986, as amended
from time to time, and the rules and regulations thereunder, and any
successor thereto.

 

“Consolidated Cash Flow” means, with respect to any Person
for any period, the Consolidated Net Income of such Person for such period
plus:

 

(1)           an amount equal to
any net loss realized by such Person and its Restricted Subsidiaries in
connection with an Asset Sale, to the extent such losses were deducted in
computing such Consolidated Net Income; plus

 

(2)           provision for taxes
based on income or profits of such Person and its Restricted Subsidiaries for
such period, to the extent that such provision for taxes was deducted in
computing such Consolidated Net Income; plus

 

(3)           the consolidated
interest expense of such Person and its Restricted Subsidiaries for such
period, whether paid or accrued (including, without limitation, amortization of
debt issuance costs and original issue discount, non-cash interest 

 

5

 

payments, the
interest component of any deferred payment obligations, the interest component
of all payments associated with Capital Lease Obligations, imputed interest
with respect to Attributable Debt, commissions, discounts and other fees and
charges incurred in respect of letter of credit or bankers’ acceptance
financings, and net of the effect of all payments made or received pursuant to
interest-rate Hedging Obligations), to the extent that any such expense was
deducted in computing such Consolidated Net Income; plus

 

(4)           depreciation,
depletion and amortization (including amortization of goodwill and other
intangibles but excluding amortization of prepaid cash expenses that were paid
in a prior period) and other non-cash expenses (excluding any such non-cash
expense to the extent that it represents an accrual of or reserve for cash
expenses in any future period or amortization of a prepaid cash expense that
was paid in a prior period) of such Person and its Restricted Subsidiaries for
such period to the extent that such depreciation, depletion, amortization,
impairment and other non-cash expenses were deducted in computing such
Consolidated Net Income; plus

 

(5)           unrealized non-cash
losses resulting from foreign currency balance sheet adjustments required by
GAAP to the extent such losses are deducted in computing such Consolidated Net
Income; plus

 

(6)           all extraordinary,
unusual or non-recurring items of gain or loss, or revenue or expense; minus

 

(7)           non-cash items
increasing such Consolidated Net Income for such period, other than items that
were accrued in the ordinary course of business, in each case, on a
consolidated basis and determined in accordance with GAAP.

 

Notwithstanding the preceding, the provision
for taxes based on the income or profits of, and the depreciation, depletion
and amortization and other non-cash charges of, a Restricted Subsidiary of the
Partnership shall be added to Consolidated Net Income to compute Consolidated
Cash Flow of the Partnership only to the extent that a corresponding amount
would be permitted at the date of determination to be dividended or distributed
to the Partnership by such Restricted Subsidiary without prior approval (that
has not been obtained), pursuant to the terms of its charter and all agreements
(other than this Indenture, the Notes or its Guarantee), instruments,
judgments, decrees, orders, statutes, rules and governmental regulations
applicable to that Restricted Subsidiary or its stockholders, partners or
members.

 

“Consolidated Net Income” means, with respect to any
specified Person for any period, the aggregate of the Net Income of such Person
and its Restricted Subsidiaries for such period, on a consolidated basis,
determined in accordance with GAAP; provided that:

 

(1)           Net Income (but not
loss) of any Person that is not a Restricted Subsidiary or that is accounted
for by the equity method of accounting will be included, but only to the extent
of the amount of dividends or distributions paid in cash to the specified
Person or a Restricted Subsidiary of the Person;

 

6

 

(2)           the Net Income of
any Restricted Subsidiary shall be excluded to the extent that the declaration
or payment of dividends or similar distributions by that Restricted Subsidiary
of that Net Income is not at the date of determination permitted without any
prior governmental approval (that has not been obtained) or, directly or
indirectly, by operation of the terms of its charter or any agreement (other
than this Indenture, the Notes or its Guarantee), instrument, judgment, decree,
order, statute, rule or governmental regulation applicable to that
Restricted Subsidiary or its stockholders, partners or members;

 

(3)           the cumulative
effect of a change in accounting principles shall be excluded;

 

(4)           unrealized losses
and gains under derivative instruments included in the determination of Consolidated
Net Income, including, without limitation, those resulting from the application
of Statement of Financial Accounting Standards No. 133, shall be excluded;
and

 

(5)           any nonrecurring
charges relating to any premium or penalty paid, write off of deferred finance
costs or other charges in connection with redeeming or retiring any
Indebtedness prior to it Stated Maturity shall be excluded.

 

“Consolidated Net Tangible Assets” means, with respect to any
Person at any date of determination, the aggregate amount of total assets
included in such Person’s most recent quarterly or annual consolidated balance
sheet prepared in accordance with GAAP less applicable reserves reflected in
such balance sheet, after deducting the following amounts: (1) all current
liabilities reflected in such balance sheet, and (2) all goodwill,
trademarks, patents, unamortized debt discounts and expenses and other like
intangibles reflected in such balance sheet.

 

“Continuing Directors”
means, as of any date of determination, any member of the Board of Directors of
the General Partner who (1) was a member of such Board of Directors on the
Issue Date or (2) was nominated for election or elected to such Board of
Directors with the approval of a majority of the Continuing Directors who were
members of such Board at the time of such nomination or election.

 

“Corporate Trust Office of the Trustee” shall be at the
address of the Trustee specified in Section 12.02 hereof or such other
address as to which the Trustee may give notice to the Issuers.

 

“Credit Agreement” means that certain Credit Agreement, dated
February 20, 2008, among the Partnership, the banks parties thereto and
Royal Bank of Canada, as administrative agent, consisting of a revolver loan
and a term loan, including any related notes, guarantees, collateral documents,
instruments and agreements executed in connection therewith, and in each case
as amended, restated, modified, renewed, refunded, replaced or refinanced in
whole or in part from time to time.

 

“Credit Facilities” means, with respect to the Partnership,
MarkWest Finance or any Restricted Subsidiary, one or more credit facilities or
commercial paper facilities, including the Credit Agreement, providing for
revolving credit loans, term loans, receivables financing 

 

7

 

(including through the sale of receivables to
lenders or to special purpose entities formed to borrow from lenders against
such receivables) or letters of credit, in each case, as amended, restated,
modified, renewed, refunded, replaced or refinanced in whole or in part from
time to time.

 

“Default” means any event that is or with the passage of time
or the giving of notice or both would be, an Event of Default.

 

“Depositary” means, with respect to the Notes issuable or
issued in whole or in part in global form, the Person specified in Section 2.03
hereof as the Depositary with respect to the Notes, and any and all successors
thereto appointed as depositary hereunder and having become such pursuant to
the applicable provision of this Indenture.

 

“Disqualified Equity” means any Equity Interest that, by its
terms (or by the terms of any security into which it is convertible, or for
which it is exchangeable, in each case at the option of the holder thereof), or
upon the happening of any event, matures or is mandatorily redeemable, pursuant
to a sinking fund obligation or otherwise, or redeemable at the option of the
holder thereof, in whole or in part, on or prior to the date that is 91 days
after the date on which the Notes mature. 
Notwithstanding the preceding sentence, any Equity Interest that would
constitute Disqualified Equity solely because the holders thereof have the
right to require the Partnership or any of its Restricted Subsidiaries to
repurchase such Equity Interests upon the occurrence of a change of control or
an asset sale shall not constitute Disqualified Equity if the terms of such
Equity Interests provide that the Partnership or Restricted Subsidiary may not
repurchase or redeem any such Equity Interests pursuant to such provisions
unless such repurchase or redemption is conditioned upon, and subject to,
compliance with Section 4.08 hereof.

 

“Distribution Compliance Period” means the 40-day
distribution compliance period as defined in Regulation S.

 

“Equity Interests” means:

 

(1)           in the case of a
corporation, corporate stock;

 

(2)           in the case of an
association or business entity, any and all shares, interests, participations,
rights or other equivalents (however designated) of corporate stock;

 

(3)           in the case of a
partnership or limited liability company, partnership or membership interests
(whether general or limited);

 

(4)           any other interest
or participation that confers on a Person the right to receive a share of the
profits and losses of, or distributions of assets of, the issuing Person; and

 

(5)           all warrants,
options or other rights to acquire any of the interests described in clauses (1) through
(4) above (but excluding any debt security that is convertible into, or
exchangeable for, any of the interests described in clauses (1) through (4) above).

 

8

 

“Equity Offering”
means any public or private sale for cash of Equity Interests of the
Partnership (excluding sales made to any Restricted Subsidiary and excluding
sales of Disqualified Equity) after the Issue Date; provided that a private
placement of Equity Interests will not be deemed an Equity Offering unless net
cash proceeds of at least $10.0 million are received.

 

“Euroclear” means the Euroclear System or any successor
securities clearing agency.

 

“Exchange Act” means the Securities Exchange Act of 1934, as
amended.

 

“Exchange Notes” means the 83⁄4% Series B Senior Notes due
2018, having terms substantially identical to the Series A Notes, offered
to the Holders of the Series A Notes under an Exchange Offer Registration
Statement.

 

“Exchange Offer” means an offer that may be made by the
Issuers pursuant to a Registration Rights Agreement to the Holders of the Series A
Notes to exchange their Series A Notes for a like aggregate principal
amount of the Exchange Notes registered under the Securities Act.

 

“Exchange Offer Registration Statement” means a registration
statement filed by the Issuers and the Subsidiary Guarantors with the SEC to
register the Exchange Notes for issuance in an Exchange Offer.

 

“Existing Indebtedness” means the aggregate principal amount
of Indebtedness of the Partnership and its Restricted Subsidiaries in existence
on the Issue Date.

 

“Fixed Charge Coverage Ratio” means, with respect to any
specified Person for any four-quarter reference period, the ratio of the
Consolidated Cash Flow of such Person for such period to the Fixed Charges of
such Person for such period.  In the
event that the specified Person or any of its Restricted Subsidiaries incurs,
assumes, guarantees, repays or redeems any Indebtedness (other than revolving
credit borrowings not constituting a permanent commitment reduction) or issues
or redeems Disqualified Equity subsequent to the commencement of the period for
which the Fixed Charge Coverage Ratio is being calculated but prior to the date
on which the event for which the calculation of the Fixed Charge Coverage Ratio
is made (the “Calculation Date”), then the Fixed Charge Coverage Ratio shall be
calculated giving pro forma effect to such incurrence, assumption, guarantee,
repayment or redemption of Indebtedness, or such issuance or redemption of
Disqualified Equity, and the application of the net proceeds thereof as if the
same had occurred at the beginning of the applicable four-quarter reference
period.

 

In addition,
for purposes of calculating the Fixed Charge Coverage Ratio:

 

(1)           acquisitions that
have been made by the specified Person or any of its Restricted Subsidiaries,
including through mergers, consolidations or otherwise (including acquisitions
of assets used in a Permitted Business), and including in each case any related
financing transactions (including repayment of Indebtedness) during the
four-quarter reference period or subsequent to such reference period and on or
prior to the Calculation Date will be given pro forma effect as if they had
occurred on the first day of 

 

9

 

the
four-quarter reference period, including any Consolidated Cash Flow and any pro
forma expense and cost reductions that have occurred or are reasonably expected
to occur, in the reasonable judgment of the chief financial or accounting
officer of the Partnership (regardless of whether those cost savings or
operating improvements could then be reflected in pro forma financial
statements in accordance with Regulation S-X promulgated under the Securities
Act or any other regulation or policy of the SEC related thereto);

 

(2)           the Consolidated
Cash Flow attributable to discontinued operations, as determined in accordance
with GAAP, and operations or businesses disposed of prior to the Calculation
Date, shall be excluded;

 

(3)           the Fixed Charges
attributable to discontinued operations, as determined in accordance with GAAP,
and operations or businesses disposed of prior to the Calculation Date, shall
be excluded, but only to the extent that the obligations giving rise to such
Fixed Charges will not be obligations of the specified Person or any of its
Restricted Subsidiaries following the Calculation Date;

 

(4)           interest on
outstanding Indebtedness of the specified Person or any of its Restricted
Subsidiaries as of the last day of the four-quarter reference period shall be
deemed to have accrued at a fixed rate per annum equal to the rate of interest
on such Indebtedness in effect on such last day after giving effect to any
Hedging Obligation then in effect; and

 

(5)           if interest on any
Indebtedness incurred by the specified Person or any of its Restricted
Subsidiaries on such date may optionally be determined at an interest rate
based upon a factor of a prime or similar rate, a eurocurrency interbank
offered rate or other rates, then the interest rate in effect on the last day
of the four-quarter reference period will be deemed to have been in effect
during such period.

 

“Fixed Charges” means, with respect to any Person for any
period, the sum, without duplication, of:

 

(1)           the consolidated
interest expense of such Person and its Restricted Subsidiaries for such
period, whether paid or accrued, including, without limitation, amortization of
debt issuance costs and original issue discount, non-cash interest payments,
the interest component of any deferred payment obligations, the interest
component of all payments associated with Capital Lease Obligations, imputed
interest with respect to Attributable Debt, commissions, discounts, and other
fees and charges incurred in respect of letter of credit or bankers’ acceptance
financings, and net of the effect of all payments made or received pursuant to interest-rate
Hedging Obligations; plus

 

(2)           the consolidated
interest expense of such Person and its Restricted Subsidiaries that was
capitalized during such period; plus

 

(3)           any interest expense
on Indebtedness of another Person that is guaranteed by such Person or one of
its Restricted Subsidiaries or secured by a Lien on assets of such 

 

10

 

Person or one
of its Restricted Subsidiaries, whether or not such guarantee or Lien is called
upon; plus

 

(4)           all dividend
payments, whether paid or accrued and whether or not in cash, on any series of
Disqualified Equity of such Person or any of its Restricted Subsidiaries, other
than dividend payments on Equity Interests payable solely in Equity Interests
of the Partnership (other than Disqualified Equity) or to the Partnership or a
Restricted Subsidiary of the Partnership;

 

in each case, on a consolidated basis and in
accordance with GAAP.

 

“GAAP” means generally accepted accounting principles in the
United States, which are in effect from time to time.

 

“General Partner” means MarkWest Energy GP, L.L.C., a
Delaware limited liability company, and its successors and permitted assigns as
general partner of the Partnership.

 

“Global Note Legend” means the legend set forth in Section 2.06(g)(ii),
which is required to be placed on all Global Notes issued under this Indenture.

 

“Global Notes” means, individually and collectively, each of
the Restricted Global Notes and the Unrestricted Global Notes, in the form of Exhibit A
hereto issued in accordance with Section 2.01, 2.06(b) or 2.06(f) hereof.

 

The term “guarantee” means a guarantee, other than by endorsement of
negotiable instruments for collection in the ordinary course of business,
direct or indirect, in any manner, including, without limitation, by way of a
pledge of assets, or through letters of credit or reimbursement, “claw-back,” “make-well,”
or “keep-well” agreements in respect thereof, of all or any part of any
Indebtedness.  The term “guarantee” used
as a verb has a corresponding meaning. 
The term “guarantor” shall mean any Person providing a guarantee of any
obligation.

 

“Guarantee” means, individually and collectively, the
guarantees given by the Subsidiary Guarantors pursuant to Article 10
hereof, including a notation in the Notes substantially in the form attached
hereto as Exhibit D.

 

“Guarantee Obligations” means, with respect to each
Subsidiary Guarantor, the obligations of such Guarantor under Article 10.

 

“Guarantor Subordinated Obligation” means, with respect to a
Subsidiary Guarantor, any Indebtedness or other Obligations of such Subsidiary
Guarantor (whether outstanding on the Issue Date or thereafter incurred) which
are expressly subordinate in right of payment to the Obligations of such
Subsidiary Guarantor under its Guarantee pursuant to a written agreement.

 

“Hedging Obligations” means, with respect to any Person, the
obligations of such Person under interest rate and commodity price swap
agreements, interest rate and commodity price cap agreements, interest rate and
commodity price collar agreements and foreign currency and commodity price
exchange agreements, options or futures contracts or other similar agreements
or arrangements or Hydrocarbon hedge contracts or Hydrocarbon forward sales
contracts, in 

 

11

 

each case designed to protect such Person
against fluctuations in interest rates, foreign exchange rates, or commodities
prices.

 

“Holder” means the Person in whose name a Note is registered
on the Registrar’s books.

 

“Hydrocarbons”
means crude oil, natural gas, casinghead gas, drip gasoline, natural gasoline,
condensate, distillate, liquid hydrocarbons, gaseous hydrocarbons and all
constituents, elements or compounds thereof and products refined or processed
therefrom.

 

“IAI Global Note” means the Global Note in the form of Exhibit A
hereto bearing the Global Note Legend and the Private Placement Legend and that
has the “Schedule of Exchange of Interests in the Global Note” attached thereto
and deposited with and registered in the name of the Depositary or its nominee
that will be issued in a denomination equal to the outstanding principal amount
of the Notes transferred to Institutional Accredited Investors in accordance
with 2.06(b)(iii)(C), subject to adjustment as provided in Section 2.06
hereof.

 

“Indebtedness” means, with respect to any specified Person,
any indebtedness of such Person, whether or not contingent:

 

(1)           in respect of
borrowed money;

 

(2)           evidenced by bonds,
notes, debentures or similar instruments or letters of credit (or reimbursement
agreements in respect thereof);

 

(3)           in respect of
bankers’ acceptances;

 

(4)           representing Capital
Lease Obligations;

 

(5)           representing all
Attributable Debt of such Person in respect of any sale and lease-back
transactions not involving a Capital Lease Obligation;

 

(6)           representing the
balance deferred and unpaid of the purchase price of any property, except any
such balance that constitutes an accrued expense or trade payable incurred in
the ordinary course of business;

 

(7)           representing
Disqualified Equity; or

 

(8)           representing any
Hedging Obligations;

 

if and to the extent any of the preceding
items (other than the item referred to in clause (5), letters of credit,
Disqualified Equity and Hedging Obligations) would appear as a liability upon a
balance sheet of the specified Person prepared in accordance with GAAP.  In addition, the term “Indebtedness” includes
all Indebtedness of others secured by a Lien on any asset of the specified
Person (whether or not such Indebtedness is assumed by the specified Person)
and, to the extent not otherwise included, the guarantee by such Person of any
Indebtedness of any other Person, provided that a guarantee otherwise permitted
by this Indenture to be incurred by the Partnership or any of its Restricted
Subsidiaries of Indebtedness incurred by the Partnership or a 

 

12

 

Restricted Subsidiary in compliance with the
terms of this Indenture shall not constitute a separate incurrence of
Indebtedness.

 

The amount of
any Indebtedness outstanding as of any date shall be:

 

(1)           the accreted value
thereof, in the case of any Indebtedness issued with original issue discount;

 

(2)           in the case of any
Hedging Obligation, the termination value of the agreement or arrangement
giving rise to such Hedging Obligation that would be payable by such Person at
such date;

 

(3)           in the case of any
letter of credit, the maximum potential liability thereunder; and

 

(4)           the principal amount
thereof, together with any interest thereon that is more than 30 days past due,
in the case of any other Indebtedness.

 

For purposes of
clause (7) of the first paragraph of this definition, Disqualified Equity
shall be valued at the maximum fixed redemption, repayment or repurchase price,
which shall be calculated in accordance with the terms of such Disqualified
Equity as if such Disqualified Equity were repurchased on any date on which
Indebtedness shall be required to be determined pursuant to this Indenture; provided,
however, that if such Disqualified Equity is not then permitted by its terms to
be redeemed, repaid or repurchased, the redemption, repayment or repurchase
price shall be the book value of such Disqualified Equity.  The amount of Indebtedness of any Person at
any date shall be the outstanding balance at such date of all unconditional
Obligations as described above and the maximum liability of any guarantees at
such date; provided that for purposes of calculating the amount of any
non-interest bearing or other discount security, such Indebtedness shall be
deemed to be the principal amount thereof that would be shown on the balance
sheet of the issuer thereof dated such date prepared in accordance with GAAP,
but that such security shall be deemed to have been incurred only on the date
of the original issuance thereof.

 

“Indenture” means this Indenture, as amended or supplemented
from time to time.

 

“Indirect Participant” means a Person who holds a beneficial
interest in a Global Note through a Participant.

 

“Initial Purchasers” means J.P. Morgan Securities Inc., RBC
Capital Markets Corporation, Wachovia Capital Markets, LLC, Banc of America
Securities LLC, Credit Suisse Securities (USA) LLC, Deutsche Bank Securities
Inc., Fortis Securities LLC and SunTrust Capital Markets, Inc.

 

“Institutional Accredited Investor” means an institution that
is an “accredited investor” as defined in Rule 501(a)(1), (2), (3) or (7) of
the rules and regulations promulgated under the Securities Act.

 

“Interest Payment Date” means Stated Maturity of an
installment of interest on the Notes.

 

13

 

“Investment Grade Rating” means a rating equal to or higher
than Baa3 (or the equivalent) by Moody’s and BBB- (or the equivalent) by
Standard & Poor’s.

 

“Investments” means, with respect to any Person, all
investments by such Person in other Persons (including Affiliates) in the forms
of direct or indirect loans (including guarantees of Indebtedness or other
Obligations), advances (other than advances to customers in the ordinary course
of business that are recorded as accounts receivable on the balance sheet of
the lender and commission, moving, travel and similar advances to officers and
employees made in the ordinary course of business) or capital contributions,
purchases or other acquisitions for consideration of Indebtedness, Equity
Interests or other securities, together with all items that are or would be
classified as investments on a balance sheet prepared in accordance with
GAAP.  For purposes of the definition of “Unrestricted
Subsidiary,” the definition of “Restricted Payment” and the covenant in Section 4.08
hereof, (1) the term “Investment” shall include the portion (proportionate
to the Partnership’s Equity
Interest in such Subsidiary) of the fair market value of the net assets of any
Subsidiary of the Partnership or any of its Restricted Subsidiaries at the time
that such Subsidiary is designated an Unrestricted Subsidiary; provided,
however, that upon a redesignation of such Subsidiary as a Restricted
Subsidiary, the Partnership or such Restricted Subsidiary shall be deemed to
continue to have a permanent “Investment” in such Subsidiary at the time
immediately before the effectiveness of such redesignation less the portion
(proportionate to the Partnership’s or such Restricted Subsidiary’s Equity
Interest in such Subsidiary) of the fair market value of the net assets of such
Subsidiary at the time of such redesignation, and (2) any property
transferred to or from an Unrestricted Subsidiary shall be valued at its fair
market value at the time of such transfer, in each case as determined in good faith
by the Board of Directors of the General Partner.  If the Partnership or any Restricted
Subsidiary of the Partnership
sells or otherwise disposes of any Equity Interests of any direct or indirect
Restricted Subsidiary of the Partnership such that, after giving effect to any such sale or disposition, such
Person is no longer a Restricted Subsidiary of the Partnership, the Partnership shall be deemed to have made an Investment
on the date of any such sale or disposition equal to the fair market value of the
Equity Interests of such Restricted Subsidiary not sold or disposed of in an
amount determined as provided in the last paragraph of Section 4.08(b) hereof.

 

“Issue Date” means April 15, 2008.

 

“Issuers” means the Partnership and MarkWest Finance, collectively;
“Issuer” means the Partnership or MarkWest Finance.

 

“Joint Venture” means any Person that is not a direct or
indirect Subsidiary of the Partnership in which the Partnership or any of its
Restricted Subsidiaries makes any Investment.

 

“Legal Holiday” means a Saturday, a Sunday or a day on which
banking institutions in the City of Denver, Colorado, Dallas, Texas or New
York, New York or at a place of payment are authorized by law, regulation or
executive order to remain closed.  If a
payment date is a Legal Holiday at a place of payment, payment may be made at
that place on the next succeeding day that is not a Legal Holiday, and no
interest shall accrue for the intervening period.

 

14

 

“Letter of Transmittal” means the letter of transmittal to be
prepared by the Issuers and sent to all Holders of the Series A Notes for
use by such Holders in connection with an Exchange Offer.

 

“Lien” means, with respect to any asset, any mortgage, lien
(statutory or otherwise), pledge, charge, security interest, hypothecation,
assignment for security, claim, preference, priority or encumbrance of any kind
in respect of such asset, whether or not filed, recorded or otherwise perfected
under applicable law, including any conditional sale or other title retention
agreement or any lease in the nature thereof, any option or other agreement to
grant a security interest in and any filing of or agreement to give any
financing statement under the Uniform Commercial Code (or equivalent statute)
of any jurisdiction other than a precautionary financing statement respecting a
lease not intended as a security agreement.

 

“Make Whole Amount” means, with respect to any Note at any
redemption date, the excess, if any, of (1) an amount equal to the present
value of (a) the redemption price of such Note at April 15, 2013 plus
(b) the remaining scheduled interest payments on the Notes to be redeemed
(subject to the right of Holders on the relevant record date to receive
interest due on the relevant Interest Payment Date) to April 15, 2013
(other than interest accrued to the redemption date), computed using a discount
rate equal to the Treasury Rate plus 50 basis points, over (2) the
aggregate principal amount of the Notes to be redeemed.

 

“MarkWest Finance” means the Person named as such in the
preamble of this Indenture under and until a successor replaces it pursuant to
the applicable provision of this Indenture and thereafter means such successor.

 

“MarkWest Hydrocarbon” means MarkWest Hydrocarbon, Inc.,
a Delaware corporation, and its successors.

 

“MarkWest Hydrocarbon Group” means, collectively, (1) John
M. Fox and any of his Affiliates, (2) MarkWest Hydrocarbon, (3) the
Partnership and (4) each Person which is a direct or indirect Subsidiary
of the Partnership.

 

“Moody’s” means Moody’s Investors Service, Inc. or any
successor to the rating agency business thereof.

 

“Net Income” means, with respect to any Person, the
consolidated net income (loss) of such Person and its Restricted Subsidiaries,
determined in accordance with GAAP and before any reduction in respect of
preferred stock dividends, excluding, however:

 

(1)                                 the
aggregate gain (but not loss in excess of such aggregate gain), together with
any related provision for taxes on such gain, realized in connection with:

 

(a)                      any
Asset Sale; or

 

(b)                     the
disposition of any securities by such Person or any of its Restricted
Subsidiaries or the extinguishment of any Indebtedness of such Person or any of
its Restricted Subsidiaries; and

 

15

 

(2)           any extraordinary
gain (but not loss), together with any related provision for taxes on such
extraordinary gain (but not loss).

 

“Net Proceeds” means, with respect to any Asset Sale or sale
of Equity Interests, the aggregate proceeds received by the Partnership or any
of its Restricted Subsidiaries in cash or Cash Equivalents in respect of any
Asset Sale or sale of Equity Interests (including, without limitation, any cash
received upon the sale or other disposition of any non-cash consideration
received in any such sale), net of, without duplication, (1) the direct
costs relating to such Asset Sale or sale of Equity Interests, including,
without limitation, brokerage commissions and legal, accounting and investment
banking fees, sales commissions, recording fees, title transfer fees and any
relocation expenses incurred as a result thereof, (2) taxes paid or
payable as a result thereof, in each case after taking into account any
available tax credits or deductions and any tax sharing arrangements and
amounts required to be applied to the repayment of Indebtedness secured by a
Lien on the asset or Equity Interests that were the subject of such Asset Sale
or sale of Equity Interests, (3) all distributions and payments required
to be made to minority interest holders in Restricted Subsidiaries as a result
of such Asset Sale and (4) any amounts to be set aside in any reserve
established in accordance with GAAP or any amount placed in escrow, in either
case for adjustment in respect of the sale price of such asset or Equity
Interests or for liabilities associated with such Asset Sale or sale of Equity
Interests and retained by the Partnership or any of its Restricted Subsidiaries
until such time as such reserve is reversed or such escrow arrangement is
terminated, in which case Net Proceeds shall include only the amount of the
reserve so reversed or the amount returned to the Partnership or its Restricted
Subsidiaries from such escrow arrangement, as the case may be.

 

“Non-Recourse Debt” means Indebtedness as to which:

 

(1)           neither the
Partnership nor any of its Restricted Subsidiaries (a) provides credit
support of any kind (including any undertaking, agreement or instrument that
would constitute Indebtedness), (b) is directly or indirectly liable as a
guarantor or otherwise, or (c) constitutes the lender of such
Indebtedness;

 

(2)           no default with
respect to which (including any rights that the holders thereof may have to
take enforcement action against an Unrestricted Subsidiary) would permit upon
notice, lapse of time or both any holder of any other Indebtedness (other than
the Notes) of the Partnership or any of its Restricted Subsidiaries to declare
a default on such other Indebtedness or cause the payment thereof to be
accelerated or payable prior to its Stated Maturity; and

 

(3)           the lenders have
been notified in writing that they will not have any recourse to the stock or
assets of the Partnership or any of its Restricted Subsidiaries, except as
contemplated by clause (15) of the definition of “Permitted Liens.”

 

“Non-U.S. Person” means a person who is not a U.S. Person.

 

“Note Custodian” means the Trustee, as custodian with respect
to the Notes in global form, or any successor entity thereto.

 

“Notes” has the meaning assigned to it in the preamble to
this Indenture.

 

16

 

“Obligations” means any principal, interest, penalties, fees,
indemnifications, reimbursement obligations, damages and other liabilities
payable under the documentation governing any Indebtedness.

 

“Offering” means the offering of the Series A Notes by
the Issuers pursuant to the Offering Memorandum.

 

“Offering Memorandum” means the offering memorandum of the
Issuers dated April 10, 2008 relating to the Offering.

 

“Officer” means, with respect to any Person, the Chairman of
the Board, the Chief Executive Officer, the President, the Chief Operating
Officer, the Chief Financial Officer, the Chief Accounting Officer, the
Treasurer, any Assistant Treasurer, the Controller, the Secretary or any
Vice-President of such Person (or, with respect to the Partnership, so long as
it remains a partnership, the General Partner).

 

“Officers’ Certificate” means a certificate signed on behalf
of each of the Partnership and MarkWest Finance by two of its Officers, one of
whom must be the principal executive officer, the principal financial officer
or the principal accounting officer of such Person, that meets the requirements
of Section 12.05 hereof.

 

“Operating Company” means MarkWest Energy Operating Company,
L.L.C., a Delaware limited liability company, and its successors.

 

“Operating Surplus” shall have the meaning assigned to such
term in the Partnership Agreement, as in effect on the Issue Date.

 

“Opinion of Counsel” means an opinion from legal counsel who
is reasonably acceptable to the Trustee, that meets the requirements of Section 12.05
hereof.  The counsel may be an employee
of or counsel to the Partnership, MarkWest Finance or the General Partner (or
any Subsidiary Guarantor, if applicable), any Subsidiary of the Partnership or
the Trustee.

 

“Participant” means, with respect to DTC, Euroclear or
Clearstream, a Person who has an account with DTC, Euroclear or Clearstream,
respectively (and, with respect to DTC, shall include Euroclear and
Clearstream).

 

“Participating Broker-Dealer” has the meaning set forth in
the Registration Rights Agreement relating to the Series A Notes issued on
the Issue Date.

 

“Partnership” means the Person named as such in the preamble
of this Indenture unless and until a successor replaces it pursuant to the
applicable provisions of this Indenture and thereafter means such successor.

 

“Partnership Agreement” means the Third Amended and Restated
Agreement of Limited Partnership of MarkWest Energy Partners, L.P., dated as of
February 21, 2008, as such may be amended, modified or supplemented from
time to time.

 

17

 

“Permitted Business”
means either (1) gathering, transporting, treating, processing, marketing
or otherwise handling Hydrocarbons, or activities or services reasonably
related or ancillary thereto including entering into Hedging Obligations to
support these businesses, or (2) any other business that generates gross
income that constitutes “qualifying income” under Section 7704(d) of
the Code.

 

“Permitted Business Investments” means Investments by the
Partnership or any of its Restricted Subsidiaries in any Unrestricted
Subsidiary of the Partnership or in any Joint Venture, provided that:

 

(1)           either (a) at
the time of such Investment and immediately thereafter, the Partnership could
incur $1.00 of additional Indebtedness under Section 4.09(a) or (b) such
investment is made with the proceeds of Incremental Funds;

 

(2)           if such Unrestricted
Subsidiary or Joint Venture has outstanding Indebtedness at the time of such
Investment, either (a) all such Indebtedness is Non-Recourse Debt with
respect to the Partnership and its Restricted Subsidiaries or (b) any
other Indebtedness of such Unrestricted Subsidiary or Joint Venture could, at
the time such Investment is made and, if later, at the time any such
Indebtedness is incurred, be incurred by the Partnership and its Restricted
Subsidiaries in accordance with the limitation on Indebtedness set forth in Section 4.09(a);
and

 

(3)           such Unrestricted
Subsidiary’s or Joint Venture’s activities are not outside the scope of the
Permitted Business.

 

“Permitted Investments” means:

 

(4)           any Investment in,
or that results in the creation of, any Restricted Subsidiary of the
Partnership;

 

(5)           any Investment in
the Partnership or in a Restricted Subsidiary of the Partnership (excluding
redemptions, purchases, acquisitions or other retirements of Equity Interests
in the Partnership);

 

(6)           any Investment in
cash or Cash Equivalents;

 

(7)           any Investment by
the Partnership or any Restricted Subsidiary of the Partnership in a Person if
as a result of such Investment:

 

(a)                                 such
Person becomes a Restricted Subsidiary of the Partnership; or

 

(b)                                such
Person is merged, consolidated or amalgamated with or into, or transfers or
conveys substantially all of its assets to, or is liquidated into, the
Partnership or a Restricted Subsidiary of the Partnership;

 

18

 

(8)           any Investment made
as a result of the receipt of consideration consisting of other than cash or
Cash Equivalents from an Asset Sale that was made pursuant to and in compliance
with Section 4.07;

 

(9)           any Investment in a
Person solely in exchange for the issuance of Equity Interests (other than
Disqualified Equity) of the Partnership;

 

(10)         Investments in stock,
obligations or securities received in settlement of debts owing to the
Partnership or any of its Restricted Subsidiaries as a result of bankruptcy or
insolvency proceedings or upon the foreclosure, perfection or enforcement of
any Lien in favor of the Partnership or any such Restricted Subsidiary, in each
case as to debt owing to the Partnership or any such Restricted Subsidiary that
arose in the ordinary course of business of the Partnership or any such
Restricted Subsidiary;

 

(11)         any Investment in
Hedging Obligations permitted to be incurred under Section 4.09 hereof;
and

 

(12)         other Investments in
any Person engaged in a Permitted Business (other than an Investment in an
Unrestricted Subsidiary) having an aggregate fair market value (measured on the
date each such Investment was made and without giving effect to subsequent
changes in value), when taken together with all other Investments made pursuant
to this clause (9) since the Issue Date and existing at the time of the
Investment, which is the subject of the determination, was made, not to exceed
the greater of (a) $25.0 million and (b) 2.50% of Consolidated Net
Tangible Assets.

 

“Permitted Liens” means:

 

(1)           Liens securing
Indebtedness under any of the Credit Facilities;

 

(2)           Liens in favor of
the Partnership or any of its Restricted Subsidiaries;

 

(3)           any interest or
title of a lessor in the property subject to a Capital Lease Obligation;

 

(4)           Liens on property of
a Person existing at the time such Person is merged with or into or
consolidated with the Partnership or any Restricted Subsidiary of the
Partnership, provided that such Liens were in existence prior to, and were not
obtained in contemplation of, such merger or consolidation and do not extend to
any assets other than those of the Person merged into or consolidated with the
Partnership or such Restricted Subsidiary;

 

(5)           Liens on property
existing at the time of acquisition thereof by the Partnership or any
Restricted Subsidiary of the Partnership, provided that such Liens were in
existence prior to, and were not obtained in contemplation of, such acquisition
and relate solely to such property, accessions thereto and the proceeds
thereof;

 

19

 

(6)           Liens to secure the
performance of tenders, bids, leases, statutory obligations, surety or appeal
bonds, government contracts, performance bonds or other obligations of a like
nature incurred in the ordinary course of business;

 

(7)           Liens on any
property or asset acquired, constructed or improved by the Partnership or any
Restricted Subsidiary, which (a) are in favor of the seller of such
property or assets, in favor of the Person constructing or improving such asset
or property, or in favor of the Person that provided the funding for the
acquisition, construction or improvement of such asset or property, (b) are
created within 360 days after the date of acquisition, construction or
improvement, (c) secure the purchase price or construction or improvement
cost, as the case may be, of such asset or property in an amount not to exceed
the lesser of (i) the cost to the Partnership and its Restricted
Subsidiaries of such acquisition, construction or improvement of such asset or
property and (ii) 100% of the fair market value (as determined by the
Board of Directors of the General Partner) of such acquisition, construction or
improvement of such asset or property, and (d) are limited to the asset or
property so acquired, constructed or improved (including proceeds thereof,
accessions thereto and upgrades thereof);

 

(8)           Liens to secure
performance of Hedging Obligations of the Partnership or any Restricted
Subsidiary;

 

(9)           Liens existing on
the Issue Date and Liens in connection with any extensions, refinancing,
renewal, replacement or defeasance of any Indebtedness or other obligation
secured thereby, provided that (a) the principal amount of the
Indebtedness secured by such Lien is not increased and (b) no assets are
encumbered by any such Lien other than the assets permitted to be encumbered
immediately prior to such extension, refinancing, renewal, replacement or
defeasance;

 

(10)         Liens on pipelines or
pipeline facilities that arise by operation of law;

 

(11)         Liens arising under
operating agreements, joint venture agreements, partnership agreements, oil and
gas leases, farmout agreements, division orders, contracts for sale,
transportation or exchange of oil and natural gas, unitization and pooling
declarations and agreements, area of mutual interest agreements and other
agreements arising in the ordinary course of the Partnership’s or any
Restricted Subsidiary’s business that are customary in the Permitted Business;

 

(12)         Liens securing the
Obligations of the Issuers under the Notes and this Indenture and of the
Subsidiary Guarantors under the Guarantees;

 

(13)         Liens upon specific
items of inventory or other goods and proceeds of any Person securing such
Person’s Obligations in respect of bankers’ acceptances issued or created for
the account of such Person to facilitate the purchase, shipment or storage of
such inventory or other goods and permitted by Section 4.09 hereof;

 

(14)         Liens securing any
Indebtedness equally and ratably with all Obligations due under the Notes or
any Guarantee pursuant to a contractual covenant that limits liens in a manner
substantially similar to Section 4.10 hereof;

 

20

 

(15)         Liens on and pledges
of the Equity Interests of any Unrestricted Subsidiaries or any Joint Venture
owned by the Partnership or any Restricted Subsidiary of the Partnership to the
extent securing Non-Recourse Debt or other Indebtedness of such Unrestricted
Subsidiary or Joint Venture; and

 

(16)         Liens incurred in the
ordinary course of business of the Partnership or any Restricted Subsidiary of
the Partnership, provided that, after giving effect to any such incurrence, the
aggregate principal amount of all Indebtedness then outstanding and secured by
any Liens incurred pursuant to this clause (16) does not exceed the greater of
$25.0 million or 2.5% of the Consolidated Net Tangible Assets of the
Partnership.

 

After the termination of the
covenants pursuant to Section 4.19 hereof, for purposes of complying with Section 4.10,
the Liens described in clauses (1) and (16) of this definition of “Permitted
Liens” shall be Permitted Liens only to the extent those Liens secure
Indebtedness not exceeding, at the time of determination, 10% of the
Consolidated Net Tangible Assets of the Partnership.  Once effective, this 10% limitation on
Permitted Liens will continue to apply during any later period in which the
Notes do not have an Investment Grade Rating from both Rating Agencies.

 

“Permitted Refinancing Indebtedness” means any Indebtedness
of the Partnership or any of its Restricted Subsidiaries issued in exchange
for, or the net proceeds of which are used to extend, refinance, renew,
replace, defease or refund other Indebtedness of the Partnership or any of its
Restricted Subsidiaries (other than intercompany Indebtedness); provided that:

 

(1)           the principal amount
of such Permitted Refinancing Indebtedness does not exceed the principal amount
of, plus accrued interest on, the Indebtedness so extended, refinanced,
renewed, replaced, defeased or refunded (plus the amount of necessary fees and
expenses incurred in connection therewith and any premiums paid on the
Indebtedness so extended, refinanced, renewed, replaced, defeased or refunded);

 

(2)           such Permitted
Refinancing Indebtedness has a final maturity date no earlier than the final
maturity date of, and has a Weighted Average Life to Maturity equal to or
greater than the Weighted Average Life to Maturity of, the Indebtedness being
extended, refinanced, renewed, replaced, defeased or refunded;

 

(3)           if the Indebtedness
being extended, refinanced, renewed, replaced, defeased or refunded is
subordinated in right of payment to the Notes or the Guarantees, such Permitted
Refinancing Indebtedness is subordinated in right of payment to, the Notes or
the Guarantees, as the case may be, on terms at least as favorable to the
Holders of Notes as those contained in the documentation governing the
Indebtedness being extended, refinanced, renewed, replaced, defeased or
refunded; and

 

(4)           such Indebtedness is
not incurred by a Restricted Subsidiary if the Partnership is the obligor on
the Indebtedness being extended, refinanced, renewed, replaced, defeased or
refunded.

 

21

 

“Person” means any individual, corporation, partnership,
joint venture, association, joint-stock company, trust, unincorporated
organization, limited liability company or government or any agency or
political subdivision thereof or any other entity.

 

“Private Placement Legend” means the legend set forth in Section 2.06(g)(i) to
be placed on all Notes issued under this Indenture except where otherwise
permitted by the provisions of this Indenture.

 

“QIB” means a “qualified institutional buyer” as defined in Rule 144A.

 

“Rating Agency” means each of Standard & Poor’s and
Moody’s, or if Standard & Poor’s or Moody’s or both shall not make a
rating on the Notes publicly available, a nationally recognized statistical
rating agency or agencies, as the case may be, selected by the Issuers (as
certified by a resolution of the Board of Directors of the General Partner)
which shall be substituted for Standard & Poor’s or Moody’s, or both,
as the case may be.

 

“Registrable Securities” has the meaning set forth in the
Registration Rights Agreement applicable to such Notes.

 

“Registration Rights Agreement” means (1) with respect
to the Series A Notes issued on the Issue Date that certain agreement
among the Issuers, the Subsidiary Guarantors and the Initial Purchasers
requiring the Issuers and the Subsidiary Guarantors to file an Exchange Offer
Registration Statement and a Shelf Registration Statement, a form of which is
attached to this Indenture as Annex B hereto, and (2) any other
registration rights agreement relating to any additional Notes issued by the
Issuers after the Issue Date pursuant to Section 2.02.

 

“Regulation S” means Regulation S promulgated by the SEC
under the Securities Act.

 

“Regulation S Global Note” means a Global Note in the form of
Exhibit A hereto bearing the Global Note Legend and the Private Placement
Legend and that has the “Schedule of Exchange of Interests in the Global Note”
attached thereto and deposited with or on behalf of and registered in the name
of the Depositary or its nominee, issued in a denomination equal to the
outstanding principal amount of the Notes initially sold in reliance on Rule 903
of Regulation S, subject to adjustment as provided in Section 2.06 hereof.

 

“Reporting Default” means a Default described in Section 6.01(d) hereof.

 

“Responsible Officer,” when used with respect to the Trustee,
means the officer in the Corporate Trust Department of the Trustee having
direct responsibility for administration of this Indenture.

 

“Restricted Certificated Note” means a Certificated Note
bearing the Private Placement Legend.

 

“Restricted Global Note” means a Global Note bearing the
Private Placement Legend and that bears the Global Note Legend and that has the
“Schedule of Exchanges of Interests in the Global Note” attached thereto.

 

22

 

“Restricted Investment” means an Investment other than a
Permitted Investment or a Permitted Business Investment.

 

“Restricted Subsidiary” of a Person means any Subsidiary of
the referenced Person that is not an Unrestricted Subsidiary.  Notwithstanding anything in this Indenture to
the contrary, each of MarkWest Finance and the Operating Company shall be a
Restricted Subsidiary of the Partnership.

 

“Rule 144” means Rule 144 promulgated by the SEC
under the Securities Act.

 

“Rule 144A” means Rule 144A promulgated by the SEC
under the Securities Act.

 

“Rule 903” means Rule 903 of Regulation S
promulgated by the SEC under the Securities Act.

 

“Rule 904” means Rule 904 of Regulation S
promulgated by the SEC under the Securities Act.

 

“SEC” means the Securities and Exchange Commission.

 

“Securities Act” means the Securities Act of 1933, as
amended.

 

“Series A Notes” has the meaning set forth in the
preamble of this Indenture.

 

“Shelf Registration Statement” means a shelf registration
statement filed with the SEC by the Issuers and the Subsidiary Guarantors in
accordance with the applicable Registration Rights Agreement to register
resales of the Series A Notes or the Exchange Notes.

 

“Significant Subsidiary” means any Subsidiary that would be a
“significant subsidiary” as defined in Article 1, Rule 1-02 of
Regulation S-X, promulgated pursuant to the Securities Act and the Exchange
Act, as such Regulation is in effect on the Issue Date.

 

“Standard & Poor’s” means Standard & Poor’s
Ratings Services, a division of The McGraw-Hill Companies, Inc., or any
successor to the rating agency business thereof.

 

“Stated Maturity” means, with respect to any installment of
interest or principal on any series of Indebtedness, the date on which such
payment of interest or principal was scheduled to be paid in the original
documentation governing such Indebtedness, and shall not include any contingent
Obligations to repay, redeem or repurchase any such interest or principal prior
to the date originally scheduled for the payment thereof.

 

“Subordinated Obligation” means any Indebtedness of the
Partnership or MarkWest Finance (whether outstanding on the Issue Date or
thereafter incurred) that is subordinate or junior in right of payment to the
Notes pursuant to a written agreement.

 

23

 

“Subsidiary” means, with respect to any Person:

 

(1)           any corporation,
association or other business entity (other than an entity referred to in
clause (2) below) of which more than 50% of the total Voting Stock is at
the time owned or controlled, directly or indirectly, by such Person or one or
more of the other Subsidiaries of that Person (or a combination thereof); and

 

(2)           any partnership
(whether general or limited), limited liability company or joint venture (a) the
sole general partner or member of which is such Person or a Subsidiary of such
Person, or (b) if there is more than a single general partner or member,
either (i) the only general partners, members, managing general partners
or managing members of which are such Person or one or more Subsidiaries of such
Person (or any combination thereof) or (ii) such Person owns or controls,
directly or indirectly, a majority of the outstanding general partner
interests, member interests or other Voting Stock of such partnership, limited
liability company or joint venture, respectively.

 

“Subsidiary Guarantors” means each of:

 

(1)           the Operating
Company, MarkWest Hydrocarbon, the General Partner, Basin Pipeline L.L.C.,
MarkWest Blackhawk, L.L.C., MarkWest Energy Appalachia, L.L.C., MarkWest Energy
East Texas Gas Company, L.L.C., MarkWest Gas Services, L.L.C., MarkWest
Javelina Company, L.L.C., MarkWest Javelina Pipeline Company, L.L.C., MarkWest
Michigan Pipeline Company, 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., MarkWest Oklahoma Gas Company, L.L.C., Mason Pipeline Limited
Liability Company, Matrex, L.L.C., MarkWest Liberty Gas Gathering, L.L.C. and
West Shore Processing Company, L.L.C.; and

 

(2)           any other Subsidiary
of the Partnership that becomes a Subsidiary Guarantor in accordance with the
provisions of Section 4.13 and Article 10 of this Indenture; and

 

(3)           their respective
successors and assigns;

 

in each case until such
Subsidiary Guarantor ceases to be such in accordance with this Indenture.  Notwithstanding anything in this Indenture to
the contrary, MarkWest Finance shall not be a Subsidiary Guarantor.

 

“Tax Payment” means any payment of foreign, federal, state or
local tax liabilities.

 

“TIA” means the Trust Indenture Act of 1939 (15 U.S.C.
Sections 77aaa-77bbbb) as in effect on the date on which this Indenture is
qualified under the TIA, except as provided in Section 9.03 hereof.

 

“Treasury
Rate” means, at the time of computation, the yield to maturity of
United States Treasury securities with a constant maturity (as compiled and
published in the most recent Federal Reserve Statistical Release H.15(519)
which has become publicly available at least two 

 

24

 

Business Days prior to the redemption date
or, if such Statistical Release is no longer published, any publicly available
source of similar market data) most nearly equal to the period from the
redemption date to April 15, 2013; provided, however, that if such
period is not equal to the constant maturity of a United States Treasury
security for which a weekly average yield is given, the Treasury Rate shall be
obtained by linear interpolation (calculated to the nearest one-twelfth of a
year) from the weekly average yields of United States Treasury securities for
which such yields are given, except that if the period from the redemption date
to April 15, 2013 is less
than one year, the weekly average yield on actually traded United States
Treasury securities adjusted to a constant maturity of one year shall be
used.  The Treasury Rate shall be
calculated on the third Business Day preceding the redemption date.  Any weekly average yields calculated by
interpolation shall be rounded to the nearest 1/100th of 1%, with any figure of
1/200th of 1% or above being rounded upward.

 

“Trustee” means the party named as such in the preamble of
this Indenture until a successor replaces it in accordance with the applicable
provisions of this Indenture and thereafter means the successor serving
hereunder.

 

“U.S. Government Obligations” means securities that are (1) direct
Obligations of the United States of America for the payment of which its full
faith and credit is pledged; (2) Obligations of a Person controlled or
supervised by and acting as an agency or instrumentality of the United States
of America the payment of which is unconditionally guaranteed as a full faith
and credit obligation by the United States of America, which, in either case
under clauses (1) or (2) above, are not callable or redeemable at the
option of the issuers thereof; or (3) depository receipts issued by a bank
or trust company as custodian with respect to any such U.S. Government
Obligations or a specific payment of interest on or principal of any such U.S.
Government Obligation held by such custodian for the account of the holder of a
depository receipt, provided that (except as required by law) such custodian is
not authorized to make any deduction from the amount payable to the holder of
such depository receipt from any amount received by the custodian in respect of
the U.S. Government Obligation evidenced by such depository receipt.

 

“U.S. Person” means a U.S. person as defined in Rule 902(k) of
Regulation S promulgated by the SEC under the Securities Act.

 

“Unrestricted Certificated Note” means one or more
Certificated Notes that do not bear and are not required to bear the Private
Placement Legend.

 

“Unrestricted Global Note” means a permanent Global Note in
the form of Exhibit A attached hereto that bears the Global Note Legend
and that has the “Schedule of Exchanges of Interests in the Global Note”
attached thereto, and that is deposited with or on behalf of and registered in
the name of the Depositary, representing a series of Notes that do not bear the
Private Placement Legend.

 

“Unrestricted Subsidiary”
means any Subsidiary of the Partnership (other than MarkWest Finance or the
Operating Company) that is designated by the Board of Directors of the General
Partner as an Unrestricted Subsidiary pursuant to a Board Resolution, but only
to the extent that such Subsidiary: (1) has
no Indebtedness owing to any Person other than the Partnership or any 

 

25

 

of its
Restricted Subsidiaries other than Non-Recourse Debt, except to the extent
permitted by subclause (2)(b) of the definition of “Permitted Business
Investments”; (2) is not a party to any agreement, contract, arrangement
or understanding with the Partnership or any Restricted Subsidiary of the Partnership unless the terms of any
such arrangement, contract, arrangement or understanding are no less favorable
to the Partnership or such Restricted
Subsidiary than those that might be obtained at the time from Persons who are
not Affiliates of the Partnership; (3) is
a Person with respect to which neither the Partnership nor any of its Restricted Subsidiaries has any direct
or indirect obligation (a) to subscribe for additional Equity Interests or
(b) to maintain or preserve such Person’s financial condition or to cause
such Person to achieve any specified levels of operating results; and (4) has
not guaranteed or otherwise directly or indirectly provided credit support for
any Indebtedness of the Partnership or
any of its Restricted Subsidiaries.  Notwithstanding anything in this Indenture to
the contrary, neither MarkWest Finance nor the Operating Company shall be
designated as an Unrestricted Subsidiary.

 

Any designation
of a Subsidiary of the Partnership as an Unrestricted Subsidiary shall be
evidenced to the Trustee by filing with the Trustee a Board Resolution of the
General Partner giving effect to such designation and an Officers’ Certificate
certifying that such designation complied with the preceding conditions and was
permitted by Section 4.08 hereof. 
If, at any time, any Unrestricted Subsidiary would fail to meet the
preceding requirements as an Unrestricted Subsidiary, it shall thereafter cease
to be an Unrestricted Subsidiary for purposes of this Indenture and any
Indebtedness of such Subsidiary shall be deemed to be incurred by a Restricted
Subsidiary of the Partnership as of such date and, if such Indebtedness is not permitted to be incurred as of such date
under Section 4.09 hereof, the Partnership shall be in default of such covenant.

 

“Voting Stock”
of any Person as of any date means the Equity Interests of such Person pursuant
to which the holders thereof have the general voting power under ordinary
circumstances to elect at least a majority of the board of directors,
managers, general partners or trustees of such Person (regardless of whether,
at the time, Equity Interests of any other class or classes shall have, or
might have, voting power by reason of the occurrence of any contingency) or,
with respect to a partnership (whether general or limited), any general partner
interest in such partnership.

 

“Weighted Average Life to Maturity” means, when applied to
any Indebtedness at any date, the number of years obtained by dividing: (1) the
sum of the products obtained by multiplying (a) the amount of each then
remaining installment, sinking fund, serial maturity or other required payments
of principal, including payment at final maturity, in respect thereof, by (b) the
number of years (calculated to the nearest one-twelfth) that will elapse
between such date and the making of such payment; by (2) the then
outstanding principal amount of such Indebtedness.

 

26

 

Section 1.02.                  Other Definitions.

 

	
  TERM

  	
   

  	
  DEFINED IN SECTION

  
	
   

  	
   

  	
   

  
	
  “Affiliate Transaction”

  	
   

  	
  4.12

  
	
  “Asset Sale Offer”

  	
   

  	
  3.09

  
	
  “Calculation Date”

  	
   

  	
  1.01 (definition of Fixed Charge Coverage
  Ratio)

  
	
  “Change of Control Offer”

  	
   

  	
  4.06(a)

  
	
  “Change of Control Payment”

  	
   

  	
  4.06(a)

  
	
  “Change of Control Payment Date”

  	
   

  	
  4.06(b)

  
	
  “Covenant Defeasance”

  	
   

  	
  8.03

  
	
  “Discharge”

  	
   

  	
  11.01(e)

  
	
  “DTC”

  	
   

  	
  2.03

  
	
  “Event of Default”

  	
   

  	
  6.01

  
	
  “Excess Proceeds”

  	
   

  	
  4.07(c)

  
	
  “Incremental Funds”

  	
   

  	
  4.08(a)

  
	
  “incur”

  	
   

  	
  4.09(a)

  
	
  “Legal Defeasance”

  	
   

  	
  8.02

  
	
  “Offer Amount”

  	
   

  	
  3.09

  
	
  “Offer Period”

  	
   

  	
  3.09

  
	
  “Paying Agent”

  	
   

  	
  2.03

  
	
  “Payment Default”

  	
   

  	
  6.01(g)

  
	
  “Permitted Debt”

  	
   

  	
  4.09(b)

  
	
  “Purchase Date”

  	
   

  	
  3.09

  
	
  “Registrar”

  	
   

  	
  2.03

  
	
  “Restricted Payments”

  	
   

  	
  4.08(a)

  

 

Section 1.03.                  Incorporation by
Reference of Trust Indenture Act.

 

Whenever this
Indenture refers to a provision of the TIA, the provision is incorporated by
reference in and made a part of this Indenture.

 

The following
TIA terms used in this Indenture have the following meanings:

 

“indenture
securities” means the Notes and the Guarantees;

 

“indenture
security holder” means a Holder of a Note;

 

“indenture to
be qualified” means this Indenture;

 

“indenture
trustee” or “institutional trustee” means the Trustee;

 

“obligor” on the Notes means the Partnership, MarkWest Finance or any
Subsidiary Guarantor and any successor obligor upon the Notes.

 

27

 

All other terms
used in this Indenture that are defined by the TIA, defined by TIA reference to
another statute or defined by SEC rule under the TIA have the meanings so
assigned to them.

 

Section 1.04.                  Rules of
Construction.

 

Unless the
context otherwise requires:

 

(1)           a term has the
meaning assigned to it;

 

(2)           an accounting term
not otherwise defined has the meaning assigned to it in accordance with GAAP;

 

(3)           “or” is not
exclusive;

 

(4)           words in the
singular include the plural, and in the plural include the singular;

 

(5)           provisions apply to
successive events and transactions; and

 

(6)           references to
sections of or rules under the Securities Act or the Exchange Act shall be
deemed to include substitute, replacement of successor sections or rules adopted
by the SEC from time to time.

 

ARTICLE 2

THE NOTES

 

Section 2.01.                  Form and Dating.

 

The Notes and
the Trustee’s certificate of authentication shall be substantially in the form
of Exhibit A hereto.  The notation
on each Note relating to the Guarantees shall be substantially in the form set
forth on Exhibit D, which is a part of this Indenture.  The Notes may have notations, legends or
endorsements required by law, stock exchange rule or usage.  Each Note shall be dated the date of its
authentication.  The Notes shall be in
minimum denominations of $2,000 or integral multiples of $1,000 in excess thereof.

 

The terms and
provisions contained in the Notes (including the Guarantees) shall constitute,
and are hereby expressly made, a part of this Indenture and the Partnership,
MarkWest Finance, the Subsidiary Guarantors, and the Trustee, by their
execution and delivery of this Indenture, expressly agree to such terms and
provisions and to be bound thereby. 
However, to the extent permitted by law, if any provision of any Note
conflicts with the express provisions of this Indenture, the provisions of this
Indenture shall govern and be controlling.

 

Notes issued in
global form shall be substantially in the form of Exhibit A attached
hereto (including the Global Note Legend and the “Schedule of Exchanges in the
Global Note” attached thereto).  Notes
issued in definitive form shall be substantially in the form of Exhibit A
attached hereto (but without the Global Note Legend, the phrase identified in
footnote 3 thereto and without the “Schedule of Exchanges of Interests in
the Global Note” attached thereto).  Each

 

28

 

Global Note shall represent such
of the outstanding Notes as shall be specified therein and each shall provide
that it shall represent the aggregate principal amount of outstanding Notes
from time to time endorsed thereon and that the aggregate principal amount of
outstanding Notes represented thereby may from time to time be reduced or
increased, as appropriate, to reflect exchanges and redemptions.  Any endorsement of a Global Note to reflect
the amount of any increase or decrease in the aggregate principal amount of
outstanding Notes represented thereby shall be made by the Trustee or the Note
Custodian, at the direction of the Trustee, in accordance with instructions
given by the Holder thereof as required by Section 2.06 hereof.

 

Section 2.02.                  Execution and
Authentication.

 

One Officer of
the Partnership and one Officer of MarkWest Finance shall sign the Notes for
the Partnership and MarkWest Finance, respectively, by manual or facsimile
signature.

 

If an Officer
whose signature is on a Note no longer holds that office at the time a Note is
authenticated, the Note shall nevertheless be valid.

 

A Note shall
not be valid until authenticated by the manual signature of the Trustee.  The signature shall be conclusive evidence
that the Note has been authenticated under this Indenture.

 

The Trustee
shall, upon a written order of the Partnership and MarkWest Finance signed by
one Officer of the Partnership and one Officer of MarkWest Finance,
authenticate (i) $400,000,000 aggregate principal amount of Notes, with
the Guarantees endorsed thereon, for original issue on the Issue Date and (ii) from
time to time thereafter any amount of additional Notes specified by the
Issuers, in each case, upon a written order of the Partnership and MarkWest
Finance signed by one Officer of the Partnership and one Officer of MarkWest
Finance.  Such order shall specify (a) the
amount of the Notes of each series to be authenticated and the date of original
issue thereof, and (b) whether the Notes are Series A Notes or
Exchange Notes.  The aggregate principal
amount of Notes of either series outstanding at any time may not exceed the
aggregate principal amount of Notes of such series authorized for issuance by
the Issuers pursuant to one or more written orders of the Issuers, except as
provided in Section 2.07 hereof. 
Subject to the foregoing, the aggregate principal amount of Notes of
either series that may be issued under this Indenture shall not be limited.

 

The Series A
Notes issued on the Issue Date and any additional Series A Notes
subsequently issued, together with the Exchange Notes issued in exchange
therefor, shall be treated as a single class for all purposes under this
Indenture, including, without limitation, waivers, amendments, redemptions and
offers to purchase.

 

The Trustee may
appoint an authenticating agent acceptable to the Issuers to authenticate
Notes.  An authenticating agent may
authenticate Notes whenever the Trustee may do so.  Each reference in this Indenture to
authentication by the Trustee includes authentication by such agent.  An authenticating agent has the same rights
as an Agent to deal with Holders or an Affiliate of either of the Issuers.

 

29

 

Section 2.03.                  Registrar and Paying Agent.

 

The
Partnership, MarkWest Finance and the Subsidiary Guarantors shall maintain in
the continental United States an office or agency where Notes may be presented
for registration of transfer or for exchange (“Registrar”) and an office or
agency where Notes may be presented for payment (“Paying Agent”).  The Registrar shall keep a register of the
Notes and of their transfer and exchange. 
The Issuers may appoint one or more co-registrars and one or more
additional paying agents.  The term “Registrar”
includes any co-registrar and the term “Paying Agent” includes any additional
paying agent.  The Issuers may change any
Paying Agent or Registrar without notice to any Holder.  The Issuers shall notify the Trustee in writing
of the name and address of any Agent not a party to this Indenture.  If the Issuers fail to appoint or maintain
another entity as Registrar or Paying Agent, the Trustee shall act as such.  The Partnership, MarkWest Finance or any of
their Subsidiaries may act as Paying Agent or Registrar.

 

The Issuers
initially appoint The Depository Trust Company (“DTC”) to act as Depositary
with respect to the Global Notes.

 

The Issuers
initially appoint the Trustee to act as the Registrar and Paying Agent and to
act as Note Custodian with respect to the Global Notes at the Corporate Trust
Office of the Trustee.

 

Section 2.04.                  Paying Agent to Hold Money in Trust.

 

The Issuers
shall require each Paying Agent other than the Trustee to agree in writing that
the Paying Agent will hold in trust for the benefit of Holders or the Trustee
all money held by the Paying Agent for the payment of principal, premium, if
any, or interest or Additional Interest, if any, on the Notes, and will notify
the Trustee of any default by the Partnership, MarkWest Finance or the
Subsidiary Guarantors in making any such payment.  While any such default continues, the Trustee
may require a Paying Agent to pay all money held by it to the Trustee.  The Issuers at any time may require a Paying
Agent to pay all money held by it to the Trustee.  Upon payment over to the Trustee, the Paying
Agent (if other than an Issuer or a Subsidiary Guarantor) shall have no further
liability for the money.  If an Issuer or
a Subsidiary Guarantor acts as Paying Agent, it shall segregate and hold in a
separate trust fund for the benefit of the Holders all money held by it as
Paying Agent.  Upon any bankruptcy or
reorganization proceedings relating to the Partnership or MarkWest Finance, the
Trustee shall serve as Paying Agent for the Notes.

 

Section 2.05.                  Holder Lists.

 

The Trustee
shall preserve in as current a form as is reasonably practicable the most
recent list available to it of the names and addresses of all Holders and shall
otherwise comply with TIA Section 312(a). 
If the Trustee is not the Registrar, the Issuers shall furnish to the
Trustee at least seven Business Days before each Interest Payment Date and at
such other times as the Trustee may request in writing, a list in such form and
as of such date as the Trustee may reasonably require of the names and
addresses of the Holders of Notes and the Issuers shall otherwise comply with
TIA Section 312(a).

 

30

 

Section 2.06.                  Transfer and Exchange.

 

(a)                                Transfer
and Exchange of Global Notes.  A Global
Note may not be transferred as a whole except by the Depositary to a nominee of
the Depositary, by a nominee of the Depositary to the Depositary or to another
nominee of the Depositary, or by the Depositary or any such nominee to a
successor Depositary or a nominee of such successor Depositary.  All Global Notes may be exchanged by the
Issuers for Certificated Notes if (i) the Issuers deliver to the Trustee
notice from the Depositary that it is unwilling or unable to continue to act as
Depositary or that it is no longer a clearing agency registered under the
Exchange Act and, in either case, a successor Depositary is not appointed by
the Issuers within 90 days after the date of such notice from the Depositary,
or (ii) if an Event of Default occurs and is continuing and the Depositary
notifies the Trustee of its decision to exchange the Global Notes for
Certificated Notes.  Whenever a Global
Note is exchanged as a whole for one or more Certificated Notes, it shall be
surrendered by the Holder thereof to the Trustee for cancellation.  Whenever a Global Note is exchanged in part
for one or more Certificated Notes, it shall be surrendered by the Holder
thereof to the Trustee and the Trustee shall make the appropriate notations to
the Schedule of Exchanges of Interests in the Global Notes attached thereto
pursuant to Section 2.01 hereof. 
All Certificated Notes issued in exchange for a Global Note or any
portion thereof shall be registered in such names, and delivered, as the Depositary
shall instruct the Trustee.  Global Notes
also may be exchanged or replaced, in whole or in part, as provided in Sections
2.07 and 2.10 hereof.  Every Note
authenticated and delivered in exchange for, or in lieu of, a Global Note or
any portion thereof, pursuant to Section 2.07 or 2.10 hereof, shall be
authenticated and delivered in the form of, and shall be, a Global Note.  A Global Note may not be exchanged for
another Note other than as provided in this Section 2.06(a); however,
beneficial interests in a Global Note may be transferred and exchanged as
provided in Section 2.06(b) or (f) hereof.

 

(b)                               Transfer
and Exchange of Beneficial Interests in the Global Notes.  The transfer and exchange of beneficial
interests in the Global Notes shall be effected through the Depositary, in
accordance with the provisions of this Indenture and the Applicable
Procedures.  Beneficial interests in the
Restricted Global Notes shall be subject to restrictions on transfer comparable
to those set forth herein to the extent required by the Securities Act.  Transfers of beneficial interests in the
Global Notes also shall require compliance with either subparagraph (i) or
(ii) below, as applicable, as well as one or more of the other following
subparagraphs as applicable:

 

(i)            Transfer of Beneficial Interests in the Same
Global Note.  Beneficial interests in any
Restricted Global Note may be transferred to Persons who take delivery thereof
in the form of a beneficial interest in the same Restricted Global Note in
accordance with the transfer restrictions set forth in the Private Placement
Legend; provided, however, that prior to the expiration of the Distribution
Compliance Period transfers of beneficial interests in the Regulation S Global
Note may not be made to a U.S. Person or for the account or benefit of a U.S.
Person (other than an Initial Purchaser). 
Beneficial interests in any Unrestricted Global Note may be transferred
only to Persons who take delivery thereof in the form of a beneficial interest
in an Unrestricted Global Note.  No
written orders or instructions shall be required to be delivered to the
Registrar to effect the transfers described in this Section 2.06(b)(i).

 

31

 

(ii)                                All
Other Transfers and Exchanges of Beneficial Interests in Global Notes.  In connection with all transfers and
exchanges of beneficial interests (other than a transfer of a beneficial
interest in a Global Note to a Person who takes delivery thereof in the form of
a beneficial interest in the same Global Note), the transferor of such
beneficial interest must deliver to the Registrar (A) a written order from
a Participant or an Indirect Participant given to the Depositary in accordance
with the Applicable Procedures directing the Depositary to credit or cause to
be credited a beneficial interest in another Global Note in an amount equal to
the beneficial interest to be transferred or exchanged and (B) instructions
given in accordance with the Applicable Procedures containing information regarding
the Participant account to be credited with such increase.  Upon an Exchange Offer by the Issuers in
accordance with Section 2.06(f) hereof, the requirements of this Section 2.06(b)(ii) shall
be deemed to have been satisfied upon receipt by the Registrar of the
instructions contained in the Letters of Transmittal delivered by the holders
of such beneficial interests in the Restricted Global Notes.  Upon satisfaction of all of the requirements
for transfer or exchange of beneficial interests in Global Notes contained in
this Indenture, the Notes and otherwise applicable under the Securities Act,
the Trustee shall adjust the principal amount of the relevant Global Note(s) pursuant
to Section 2.06(h) hereof.

 

(iii)                             Transfer
of Beneficial Interests to Another Restricted Global Note.  A beneficial interest in any Restricted
Global Note may be transferred to a Person who takes delivery thereof in the
form of a beneficial interest in another Restricted Global Note if the transfer
complies with the requirements of clause (ii) above and the Registrar
receives the following:

 

(A)          if
the transferee will take delivery in the form of a beneficial interest in the
144A Global Note, then the transferor must deliver a certificate in the form of
Exhibit B hereto, including the certifications in item (1) thereof;

 

(B)           if
the transferee will take delivery in the form of a beneficial interest in the
Regulation S Global Note, then the transferor must deliver a certificate in the
form of Exhibit B hereto, including the certifications in item (2) thereof;
and

 

(C)           if
the transferee will take delivery in the form of a beneficial interest in the
IAI Global Note, then the transferor must deliver (x) a certificate in the
form of Exhibit B hereto, including the certifications and certificates
and Opinion of Counsel required by item (3)(c) thereof, if applicable.

 

(iv)                             Transfer
and Exchange of Beneficial Interests in a Restricted Global Note for Beneficial
Interests in the Unrestricted Global Note. 
A beneficial interest in any Restricted Global Note may be exchanged by
any holder thereof for a beneficial interest in an Unrestricted Global Note or
transferred to a Person who takes delivery thereof in the form of a beneficial
interest in an Unrestricted Global Note if the exchange or transfer complies
with the requirements of clause (ii) above and:

 

32

 

(A)                             such
exchange or transfer is effected pursuant to an Exchange Offer in accordance
with the applicable Registration Rights Agreement and the holder of the
beneficial interest to be transferred, in the case of an exchange, or the
transferee, in the case of a transfer, is not (i) a broker-dealer, (ii) a
Person participating in the distribution of the Exchange Notes or (iii) a
Person who is an affiliate (as defined in Rule 144) of the Partnership;

 

(B)                               any
such transfer is effected pursuant to a Shelf Registration Statement in
accordance with the applicable Registration Rights Agreement;

 

(C)                               any
such transfer is effected by a Participating Broker-Dealer pursuant to an
Exchange Offer Registration Statement in accordance with the applicable
Registration Rights Agreement; or

 

(D)                              the
Registrar receives the following:

 

(i)             if
the holder of such beneficial interest in a Restricted Global Note proposes to
exchange such beneficial interest for a beneficial interest in an Unrestricted
Global Note, a certificate from such holder in the form of Exhibit C
hereto, including the certifications in item (1)(a) thereof;

 

(ii)            if
the holder of such beneficial interest in a Restricted Global Note proposes to
transfer such beneficial interest to a Person who shall take delivery thereof
in the form of a beneficial interest in an Unrestricted Global Note, a
certificate from such holder in the form of Exhibit B hereto, including
the certifications in item (4) thereof; and

 

(iii)           in
each such case set forth in this subparagraph (D), an opinion of counsel in form reasonably acceptable to the
Issuers to the effect that such exchange or transfer is in compliance with the
Securities Act, that the restrictions on transfer contained herein and in the
Private Placement Legend are not required in order to maintain compliance with
the Securities Act and such beneficial interest is being exchanged or
transferred in compliance with any applicable blue sky securities laws of any
state of the United States.

 

If any such
transfer is effected pursuant to subparagraph (B) or (D) above at a
time when an Unrestricted Global Note has not yet been issued, the Issuers
shall issue and, upon receipt of an authentication order in accordance with Section 2.02
hereof, the Trustee shall authenticate one or more Unrestricted Global Notes
(accompanied by a notation of the Guarantees duly endorsed by the Subsidiary
Guarantors) in an aggregate principal amount equal to the principal amount of
beneficial interests transferred pursuant to subparagraph (B) or (D) above.

 

Beneficial
interests in an Unrestricted Global Note cannot be exchanged for, or
transferred to Persons who take delivery thereof in the form of, a beneficial
interest in a Restricted Global Note.

 

33

 

(c)                                 Transfer
or Exchange of Beneficial Interests for Certificated Notes.  A beneficial interest in a Global Note cannot
be exchanged for, or transferred to Persons who take delivery thereof in the
form of, a Certificated Note, except in the circumstances specified in Section 2.06(a).

 

(d)                                Transfer
and Exchange of Certificated Notes for Beneficial Interests.  Certificated Notes cannot be exchanged for,
or transferred to Persons who take delivery thereof in the form of, a
beneficial interest in a Global Note.

 

(e)                                 Transfer
and Exchange of Certificated Notes for Certificated Notes.  Upon request by a Holder of Certificated
Notes and such Holder’s compliance with the provisions of this Section 2.06(e),
the Registrar shall register the transfer or exchange of Certificated
Notes.  Prior to such registration of
transfer or exchange, the requesting Holder shall present or surrender to the
Registrar the Certificated Notes duly endorsed or accompanied by a written
instruction of transfer in form satisfactory to the Registrar duly executed by
such Holder or by his attorney, duly authorized in writing.  In addition, the requesting Holder shall
provide any additional certifications, documents and information, as
applicable, pursuant to the provisions of this Section 2.06(e).

 

(i)             Restricted
Certificated Notes may be transferred to and registered in the name of Persons
who take delivery thereof if the Registrar receives the following:

 

(A)          if
the transfer will be made pursuant to Rule 144A under the Securities Act,
then the transferor must deliver a certificate in the form of Exhibit B
hereto, including the certifications in item (1) thereof;

 

(B)           if
the transfer will be made pursuant to Rule 903 or Rule 904, then the
transferor must deliver a certificate in the form of Exhibit B hereto,
including the certifications in item (2) thereof; and

 

(C)           if
the transfer will be made pursuant to any other exemption from the registration
requirements of the Securities Act, then the transferor must deliver a
certificate in the form of Exhibit B hereto, including the certifications,
certificates and Opinion of Counsel required by item (3) thereof, if
applicable.

 

(ii)           Any Restricted Certificated Note may be exchanged
by the Holder thereof for an Unrestricted Certificated Note or transferred to a
Person or Persons who take delivery thereof in the form of an Unrestricted
Certificated Note if:

 

(A)          such
exchange or transfer is effected pursuant to an Exchange Offer in accordance
with the applicable Registration Rights Agreement and the Holder, in the case
of an exchange, or the transferee, in the case of a transfer, is not (i) a
broker-dealer, (ii) a Person participating in the distribution of the
Exchange Notes or (iii) a Person who is an affiliate (as defined in Rule 144)
of the Partnership;

 

(B)           any
such transfer is effected pursuant to a Shelf Registration Statement in
accordance with the applicable Registration Rights Agreement;

 

34

 

(C)           any
such transfer is effected by a Participating Broker-Dealer pursuant to an
Exchange Offer Registration Statement in accordance with the applicable
Registration Rights Agreement; or

 

(D)          the
Registrar receives the following:

 

(i)            if the Holder of such Restricted Certificated
Notes proposes to exchange such Notes for an Unrestricted Certificated Note, a
certificate from such Holder in the form of Exhibit C hereto, including
the certifications in item (1)(b) thereof;

 

(ii)           if the Holder of such Restricted Certificated Notes
proposes to transfer such Notes to a Person who shall take delivery thereof in
the form of an Unrestricted Certificated Note, a certificate from such Holder
in the form of Exhibit B hereto, including the certifications in item (4) thereof;
and

 

(iii)          in each such case set forth in this subparagraph
(D), an opinion of counsel in form reasonably acceptable to the Issuers to the
effect that such exchange or transfer is in compliance with the Securities Act,
that the restrictions on transfer contained herein and in the Private Placement
Legend are not required in order to maintain compliance with the Securities
Act, and such Restricted Certificated Note is being exchanged or transferred in
compliance with any applicable blue sky securities laws of any state of the
United States.

 

(iii)          A Holder of Unrestricted Certificated Notes may
transfer such Notes to a Person who takes delivery thereof in the form of an
Unrestricted Certificated Note.  Upon
receipt of a request for such a transfer, the Registrar shall register the
Unrestricted Certificated Notes pursuant to the instructions from the Holder
thereof.  Unrestricted Certificated Notes
cannot be exchanged for or transferred to Persons who take delivery thereof in
the form of a Restricted Certificated Note.

 

(f)            Exchange
Offer.  Upon the occurrence of an
Exchange Offer in accordance with a Registration Rights Agreement, the Issuers
shall issue and, upon receipt of an authentication order in accordance with Section 2.02,
the Trustee shall authenticate (i) one or more Unrestricted Global Notes
(accompanied by a notation of the Guarantees duly endorsed by the Subsidiary
Guarantors) in an aggregate principal amount equal to the principal amount of
the beneficial interests in the Restricted Global Notes tendered for acceptance
by Persons that are not (x) broker-dealers (excluding broker-dealers that
acquired such beneficial interests in Restricted Global Notes as a result of
market-making activities or other trading activities (other than such
beneficial interests in Restricted Global Notes acquired directly from the
Issuers or any of their affiliates (as defined in Rule 144) thereof)), (y) Persons
participating in the distribution of the Exchange Notes or (z) Persons who
are affiliates of the Partnership and accepted for exchange in the Exchange
Offer and (ii) Unrestricted Certificated Notes (accompanied by a notation
of the Guarantees duly endorsed by the Subsidiary Guarantors) in an aggregate
principal amount equal to the principal amount of the Restricted Certificated
Notes accepted for exchange in the 

 

35

 

Exchange Offer.  Concurrently with the issuance of such Notes,
the Trustee shall cause the aggregate principal amount of the applicable
Restricted Global Notes to be reduced accordingly, and the Issuers shall
execute and the Trustee shall authenticate and deliver to the Persons
designated by the Holders of Restricted Certificated Notes so accepted Unrestricted
Certificated Notes in the appropriate principal amount.

 

(g)           Legends.  The following legends shall appear on the
face of all Global Notes and Certificated Notes issued under this Indenture
unless specifically stated otherwise in the applicable provisions of this
Indenture.

 

(i)            Private
Placement Legend.

 

(A)          Except as permitted by subparagraph (B) below,
each Global Note and each Certificated Note (and all Notes issued in exchange
therefor or substitution thereof) shall bear the legend in substantially the
following form:

 

“THIS SECURITY
HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES
ACT”), OR THE SECURITIES LAWS OF ANY STATE OR OTHER JURISDICTION.  NEITHER THIS SECURITY NOR ANY INTEREST OR
PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED,
PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH
REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO, SUCH
REGISTRATION.  THE HOLDER OF THIS
SECURITY, BY ITS ACCEPTANCE HEREOF, AGREES ON ITS OWN BEHALF AND ON BEHALF OF
ANY INVESTOR ACCOUNT FOR WHICH IT HAS PURCHASED SECURITIES, TO OFFER, SELL OR
OTHERWISE TRANSFER SUCH SECURITY, PRIOR TO THE DATE (THE “RESALE RESTRICTION
TERMINATION DATE”) THAT IS [IN THE CASE OF NOTES SOLD IN RELIANCE ON RULE 144A
UNDER THE SECURITIES ACT:  ONE
YEAR] [IN THE CASE OF NOTES SOLD IN RELIANCE ON REGULATION
S UNDER THE SECURITIES ACT: 40 DAYS] AFTER THE LATER OF THE ORIGINAL
ISSUE DATE HEREOF AND THE LAST DATE ON WHICH EITHER ISSUER OR ANY AFFILIATE OF
EITHER ISSUER WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR OF SUCH
SECURITY), ONLY (A) TO AN ISSUER OR ITS SUBSIDIARY, (B) PURSUANT TO A
REGISTRATION STATEMENT THAT HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES
ACT, (C) FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO
RULE 144A UNDER THE SECURITIES ACT, TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED
INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT THAT
PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL
BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON
RULE 144A, (D) PURSUANT TO OFFERS AND SALES THAT OCCUR OUTSIDE THE UNITED
STATES WITHIN THE MEANING OF REGULATION S UNDER 

 

36

 

THE SECURITIES
ACT, (E) TO AN INSTITUTIONAL “ACCREDITED INVESTOR” WITHIN THE MEANING OF
RULE 501(a)(1), (2), (3) OR (7) UNDER THE SECURITIES ACT THAT IS AN
INSTITUTIONAL ACCREDITED INVESTOR ACQUIRING THE SECURITY FOR ITS OWN ACCOUNT OR
FOR THE ACCOUNT OF SUCH AN INSTITUTIONAL ACCREDITED INVESTOR, IN EACH CASE IN A
MINIMUM PRINCIPAL AMOUNT OF THE SECURITIES OF $250,000, FOR INVESTMENT PURPOSES
AND NOT WITH A VIEW TO OR FOR OFFER OR SALE IN CONNECTION WITH ANY DISTRIBUTION
IN VIOLATION OF THE SECURITIES ACT, OR (F) PURSUANT TO ANOTHER AVAILABLE
EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT, SUBJECT TO
THE ISSUERS’ AND THE TRUSTEE’S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER
PURSUANT TO CLAUSES (C), (D), (E) OR (F) TO REQUIRE THE DELIVERY OF
AN OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION SATISFACTORY TO
EACH OF THEM.  THIS LEGEND WILL BE
REMOVED UPON THE REQUEST OF THE HOLDER AFTER THE RESALE RESTRICTION TERMINATION
DATE.”

 

(B)           Notwithstanding the foregoing, any Global Note or
Certificated Note issued pursuant to subparagraphs (b)(iv), (e)(ii), (e)(iii) or
(f) of this Section 2.06 (and all Notes issued in exchange therefor or
substitution thereof) shall not bear the Private Placement Legend.

 

(ii)           Global
Note Legend.  Each Global Note shall bear
a legend in substantially the following form:

 

“THIS GLOBAL
NOTE IS HELD BY THE DEPOSITARY (AS DEFINED IN THE INDENTURE GOVERNING THIS
NOTE) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS
HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT
THAT (I) THE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY BE
REQUIRED PURSUANT TO SECTION 2.06 OF THE INDENTURE, (II) THIS GLOBAL
NOTE MAY BE EXCHANGED PURSUANT TO SECTION 2.06(a) OF THE
INDENTURE, (III) THIS GLOBAL NOTE MAY BE DELIVERED TO THE TRUSTEE FOR
CANCELLATION PURSUANT TO SECTION 2.11 OF THE INDENTURE AND (IV) THIS
GLOBAL NOTE MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITARY WITH THE PRIOR
WRITTEN CONSENT OF THE ISSUERS.”

 

“UNLESS AND
UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN DEFINITIVE FORM,
THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A
NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY
OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE
TO A SUCCESSOR 

 

37

 

DEPOSITARY OR A
NOMINEE OF SUCH SUCCESSOR DEPOSITARY. 
UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF
THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (“DTC”), TO
THE ISSUERS OR THEIR AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR
SUCH OTHER NAME AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC
(AND ANY PAYMENT IS MADE TO CEDE & CO. OR SUCH OTHER ENTITY AS MAY BE
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR
OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.”

 

(h)           Cancellation
and/or Adjustment of Global Notes.  At
such time as all beneficial interests in a particular Global Note have been
exchanged for Certificated Notes or a particular Global Note has been redeemed,
repurchased or canceled in whole and not in part, each such Global Note shall
be returned to or retained and canceled by the Trustee in accordance with Section 2.11
hereof.  At any time prior to such
cancellation, if any beneficial interest in a Global Note is exchanged for or
transferred to a Person who will take delivery thereof in the form of a
beneficial interest in another Global Note or for Certificated Notes, the
principal amount of Notes represented by such Global Note shall be reduced
accordingly and an endorsement shall be made on such Global Note, by the
Trustee or by the Depositary at the direction of the Trustee, to reflect such
reduction; and if the beneficial interest is being exchanged for or transferred
to a Person who will take delivery thereof in the form of a beneficial interest
in another Global Note, such other Global Note shall be increased accordingly
and an endorsement shall be made on such Global Note, by the Trustee or by the
Depositary at the direction of the Trustee, to reflect such increase.

 

(i)            General
Provisions Relating to Transfers and Exchanges.

 

(i)            To permit registrations of transfers and
exchanges, the Issuers shall execute and the Trustee shall authenticate Global
Notes and Certificated Notes (in each case, accompanied by a notation of the
Guarantees duly endorsed by the Subsidiary Guarantors) upon the Issuers’ order
or at the Registrar’s request.

 

(ii)           No service charge shall be made to a holder of a
beneficial interest in a Global Note or to a Holder of a Certificated Note for
any registration of transfer or exchange, but the Issuers may require payment
of a sum sufficient to cover any transfer tax or similar governmental charge
payable in connection therewith (other than any such transfer taxes or similar
governmental charge payable upon exchange or transfer pursuant to Sections
2.10, 3.06, 3.09, 4.06 and 9.05 hereof).

 

(iii)          The Registrar shall not be required to register the
transfer of or exchange any Note selected for redemption in whole or in part,
except the unredeemed portion of any Note being redeemed in part.

 

38

 

(iv)          All Global Notes and Certificated Notes (in each
case, accompanied by a notation of the Guarantees duly endorsed by the
Subsidiary Guarantors) issued upon any registration of transfer or exchange of
Global Notes or Certificated Notes shall be the valid obligations of the
Issuers and the Subsidiary Guarantors, evidencing the same debt, and entitled
to the same benefits under this Indenture, as the Global Notes or Certificated
Notes surrendered upon such registration of transfer or exchange.

 

(v)           The Issuers shall not be required (A) to
issue, to register the transfer of or to exchange Notes during a period of 15
days before a selection of Notes for redemption, (B) to register the
transfer of or to exchange any Note so selected for redemption in whole or in
part, except the unredeemed portion of any Note being redeemed in part or (C) to
register the transfer of or to exchange a Note between a record date and the
next succeeding Interest Payment Date.

 

(vi)          Prior to due presentment for the registration of a
transfer of any Note, the Trustee, any Agent, the Issuers and the Subsidiary
Guarantors may deem and treat the Person in whose name any Note is registered
as the absolute owner of such Note for the purpose of receiving payment of
principal of and interest on such Notes and for all other purposes, and none of
the Trustee, any Agent, the Issuers or any Subsidiary Guarantor shall be
affected by notice to the contrary.

 

(vii)         The Trustee shall authenticate Global Notes and
Certificated Notes (in each case, accompanied by a notation of the Guarantees
duly endorsed by the Subsidiary Guarantors) in accordance with the provisions
of Section 2.02 hereof.

 

(viii)        All certifications, certificates
and opinions of counsel required to be submitted to the Registrar pursuant to
this Section 2.06 to effect a transfer or exchange may be submitted by
facsimile.

 

(ix)           Each Holder of a Note agrees to indemnify the
Issuers and the Trustee against any liability that may result from the
transfer, exchange or assignment of such Holder’s Note in violation of any
provision of this Indenture and/or applicable United States federal or state securities
law.

 

(j)            Each
beneficial owner of an interest in a Note agrees to indemnify the Issuers and
the Trustee against any liability that may result from the transfer, exchange
or assignment by such beneficial owner of such interest in violation of any provision
of this Indenture and/or applicable United States federal or state securities
law.

 

(k)           The
Trustee shall have no obligation or duty to monitor, determine or inquire as to
compliance with any restrictions on transfer imposed under this Indenture or
under applicable law with respect to any transfer of any interest in any Note
(including any transfers between or among beneficial owners of interest in any
Global Note) other than to require delivery of such certificate and other
documentation or evidence as are expressly required by, and to do so if and
when expressly required by the terms of, this Indenture, and to examine the
same to determine substantial compliance as to form with the express
requirements hereof.

 

39

 

Section 2.07.                  Replacement Notes.

 

If any
mutilated Note is surrendered to the Trustee or either of the Issuers and the
Trustee receives evidence to its satisfaction of the destruction, loss or theft
of any Note, the Issuers shall issue and the Trustee, upon the written order of
the Issuers signed by one Officer of the Partnership and one Officer of
MarkWest Finance, shall authenticate a replacement Note (accompanied by a
notation of the Guarantees duly endorsed by the Subsidiary Guarantors) if the
Trustee’s requirements are met.  An
indemnity bond must be supplied by the Holder that is sufficient in the
judgment of the Trustee and the Issuers to protect the Issuers, the Subsidiary
Guarantors, the Trustee, any Agent and any authenticating agent from any loss
that any of them may suffer if a Note is replaced.  The Issuers may charge for their expenses in
replacing a Note.

 

Every
replacement Note is an additional obligation of the Issuers and the Subsidiary
Guarantors and shall be entitled to all of the benefits of this Indenture
equally and proportionately with all other Notes duly issued hereunder.  The provisions of this Section 2.07 are
exclusive and shall preclude (to the extent lawful) all other rights and
remedies with respect to the replacement of mutilated, destroyed, lost or
stolen Notes.

 

Section 2.08.                  Outstanding Notes.

 

The Notes
outstanding at any time are all the Notes authenticated by the Trustee except
for those canceled by it, those delivered to it for cancellation, those reductions
in the interests in a Global Note effected by the Trustee in accordance with
the provisions hereof, and those described in this Section as not
outstanding.  Except as set forth in Section 2.09
hereof, a Note does not cease to be outstanding because an Issuer or an
Affiliate of an Issuer holds the Note.

 

If a Note is
replaced pursuant to Section 2.07 hereof, it ceases to be outstanding
unless the Trustee receives proof satisfactory to it that the replaced Note is
held by a bona fide purchaser.

 

If the principal
amount of any Note is considered paid under Section 4.01 hereof, it ceases
to be outstanding and interest (including Additional Interest, if applicable)
on it ceases to accrue.

 

If the Paying
Agent (other than an Issuer or a Subsidiary or an Affiliate of an Issuer)
holds, on a redemption date or other maturity date, money sufficient to pay
Notes payable on that date, then on and after that date such Notes shall be
deemed to be no longer outstanding and shall cease to accrue interest
(including Additional Interest, if any).

 

Section 2.09.                  Treasury Notes.

 

In determining
whether the Holders of the required principal amount of Notes have concurred in
any direction, waiver or consent, Notes owned by an Issuer, by any Subsidiary
Guarantor or by any Person directly or indirectly controlling or controlled by
or under direct or indirect common control with the Partnership or any
Subsidiary Guarantor, shall be considered as though not outstanding, except
that for the purposes of determining whether the Trustee shall be protected in
relying on any such direction, waiver or consent, only Notes that a Responsible
Officer of the Trustee actually knows are so owned shall be so disregarded.

 

40

 

Section 2.10.                  Temporary Notes.

 

Until
definitive Notes are ready for delivery, the Issuers may prepare and the
Trustee shall authenticate temporary Notes (accompanied by a notation of the
Guarantees duly endorsed by the Subsidiary Guarantors) upon a written order of
the Issuers signed by one Officer of the Partnership and one Officer of
MarkWest Finance.  Temporary Notes shall
be substantially in the form of definitive Notes but may have variations that
the Issuers consider appropriate for temporary Notes and as shall be reasonably
acceptable to the Trustee.  Without
unreasonable delay, the Issuers shall prepare and the Trustee shall
authenticate definitive Notes (accompanied by a notation of the Guarantees duly
endorsed by the Subsidiary Guarantors) in exchange for temporary Notes.

 

Holders of
temporary Notes shall be entitled to all of the benefits of this Indenture.

 

Section 2.11.                  Cancellation.

 

Either of the
Issuers at any time may deliver Notes to the Trustee for cancellation.  The Registrar and Paying Agent shall forward
to the Trustee any Notes surrendered to them for registration of transfer,
exchange or payment.  The Trustee and no
one else shall cancel all Notes surrendered for registration of transfer,
exchange, payment, replacement or cancellation and shall treat such canceled
Notes in accordance with its documents retention policies.  The Issuers may not issue new Notes to
replace Notes that have been paid or that have been delivered to the Trustee
for cancellation.

 

Section 2.12.                  Defaulted Interest.

 

If any of the
Partnership, MarkWest Finance or any Subsidiary Guarantor defaults in a payment
of interest on the Notes, it or they (to the extent of their obligations under
the Guarantees) shall pay the defaulted interest in any lawful manner plus, to
the extent lawful, interest payable on the defaulted interest, to the Persons
who are Holders on a subsequent special record date, in each case at the rate
provided in the Notes and in Section 4.01 hereof.  The Issuers shall notify the Trustee in
writing of the amount of defaulted interest proposed to be paid on each Note,
the special record date and the date of the proposed payment.  The Issuers shall fix or cause to be fixed
each such special record date and payment date, provided that no such special
record date shall be less than 10 days prior to the related payment date for
such defaulted interest.  At least 15
days before the special record date, the Issuers (or, upon the written request
of the Issuers, the Trustee in the name and at the expense of the Issuers)
shall mail or cause to be mailed to Holders a notice that states the special
record date, the related payment date and the amount of such interest to be
paid.

 

Section 2.13.                  CUSIP Numbers.

 

The Issuers in
issuing the Notes may use “CUSIP” numbers (if then generally in use), and, if
they do so, the Trustee shall use “CUSIP” numbers in notices of redemption as a
convenience to Holders; provided that any such notice may state that no
representation is made as to the correctness of such numbers either as printed
on the Notes or as contained in any notice of a redemption and that reliance
may be placed only on the other identification numbers printed 

 

41

 

on the Notes, and any such redemption shall
not be affected by any defect in or omission of such numbers.  The Issuers will promptly notify the Trustee
of any change in the “CUSIP” numbers.

 

ARTICLE 3

REDEMPTION AND PREPAYMENT

 

Section 3.01.                  Notices to Trustee.

 

If an Issuer
elects to redeem Notes pursuant to the optional redemption provisions of Section 3.07
hereof, it shall furnish to the Trustee, at least ten Business Days (unless a
shorter period is acceptable to the Trustee) before the date of giving notice
of the redemption pursuant to Section 3.03, an Officers’ Certificate
setting forth (i) the clause of this Indenture pursuant to which the
redemption shall occur, (ii) the redemption date, (iii) the principal
amount of Notes to be redeemed, (iv) the redemption price and (v) whether
it requests the Trustee to give notice of such redemption.  Any such notice may be cancelled at any time
prior to the mailing of notice of such redemption to any Holder and shall
thereby be void and of no effect.

 

Section 3.02.                  Selection of Notes to Be Redeemed.

 

If less than
all of the Notes are to be redeemed at any time, the Trustee will select Notes
for redemption as follows:

 

(a)           if
the Notes are listed for trading on a national securities exchange, in
compliance with the requirements of the principal national securities exchange
on which the Notes are so listed; or

 

(b)           if
the Notes are not so listed or there are no such requirements, on a pro rata
basis, by lot or by such method as the Trustee shall deem fair and appropriate.

 

No Notes of
$2,000 or less shall be redeemed in part. 
Notices of redemption shall be mailed by first class mail at least 30
but not more than 60 days before the redemption date to each Holder of Notes to
be redeemed at its registered address. 
Notices of redemption may not be conditional.

 

If any Note is
to be redeemed in part only, the notice of redemption that relates to that Note
shall state the portion of the principal amount thereof to be redeemed.  A new Note in principal amount equal to the
unredeemed portion of the original Note will be issued in the name of the Holder
thereof upon cancellation of the original Note. 
Notes called for redemption become due on the date fixed for
redemption.  On and after the redemption
date, interest (including Additional Interest, if applicable) ceases to accrue
on Notes or portions of them called for redemption unless the Issuers default
in making such redemption payment.

 

Section 3.03.                  Notice of Redemption.

 

At least 30
days but not more than 60 days before a redemption date, except that redemption
notices may be mailed more than 60 days prior to a redemption date if the
notice is issued in connection with a Legal Defeasance, Covenant Defeasance or
Discharge, the Issuers 

 

42

 

shall mail or cause to be mailed, by first
class mail, a notice of redemption to each Holder whose Notes are to be
redeemed at its registered address.

 

The notice
shall identify the Notes to be redeemed (including CUSIP numbers) and shall
state:

 

(a)           the
redemption date;

 

(b)           the
redemption price (if then determined and otherwise the basis for its
determination);

 

(c)           if
any Note is being redeemed in part, the portion of the principal amount of such
Note to be redeemed and that, after the redemption date upon surrender of such
Note, a new Note or Notes in principal amount equal to the unredeemed portion
shall be issued upon cancellation of the original Note;

 

(d)           the
name and address of the Paying Agent;

 

(e)           that
Notes called for redemption (other than a Global Note) must be surrendered to
the Paying Agent to collect the redemption price;

 

(f)            that,
unless the Issuers default in making such redemption payment, interest
(including Additional Interest, if applicable) on Notes called for redemption
ceases to accrue on and after the redemption date;

 

(g)           the
paragraph of the Notes and/or Section of this Indenture pursuant to which
the Notes called for redemption are being redeemed; and

 

(h)           that
no representation is made as to the correctness or accuracy of the CUSIP
number, if any, listed in such notice or printed on the Notes.

 

If any of the
Notes to be redeemed is in the form of a Global Note, then the Issuers shall
modify such notice to the extent necessary to accord with the procedures of the
Depositary applicable to redemption.

 

At the Issuers’
request, the Trustee shall give the notice of redemption in the Issuers’ names
and at their expense; provided, however, that the Issuers shall have delivered
to the Trustee, as provided in Section 3.01, an Officers’ Certificate
requesting that the Trustee give such notice and setting forth the information
to be stated in such notice as provided in the preceding paragraph.

 

Section 3.04.                  Effect of Notice of Redemption.

 

Once notice of
redemption is mailed in accordance with Section 3.03 hereof, Notes called
for redemption become irrevocably due and payable on the redemption date at the
redemption price.  A notice of redemption
may not be conditional.

 

43

 

Section 3.05.          Deposit of Redemption
Price.

 

Not later than 11:00 a.m.,
New York City time, on the redemption date, the Issuers shall deposit with the
Trustee or with the Paying Agent (or, if the Partnership or a Subsidiary
thereof is acting as its own Paying Agent, segregate and hold in trust as
provided in Section 2.04 hereof) money sufficient to pay the redemption
price of, and accrued and unpaid interest (including Additional Interest, if
applicable) on, all Notes to be redeemed on that date.  The Trustee or the Paying Agent shall
promptly return to the Issuers any money deposited with the Trustee or the
Paying Agent by the Issuers in excess of the amounts necessary to pay the
redemption price of, and accrued and unpaid interest (including Additional Interest,
if applicable) on, all Notes to be redeemed.

 

If the Issuers comply with the
provisions of the preceding paragraph, on and after the redemption date,
interest (including Additional Interest, if applicable) shall cease to accrue
on the Notes or the portions of Notes called for redemption.  If a Note is redeemed on or after an interest
record date but on or prior to the related Interest Payment Date, then any
accrued and unpaid interest (including Additional Interest, if any) shall be
paid to the Person in whose name such Note was registered at the close of
business on such record date.  If any
Note called for redemption shall not be so paid upon surrender for redemption
because of the failure of the Issuers to comply with the preceding paragraph,
interest (including Additional Interest, if any) shall be paid on the unpaid
principal, from the redemption date until such principal is paid, and to the
extent lawful on any interest not paid on such unpaid principal, in each case
at the rate provided in the Notes and in Section 4.01 hereof.

 

Section 3.06.          Notes Redeemed in Part.

 

Upon surrender of a Note that is
redeemed in part, the Issuers shall issue and, upon the Issuers’ written
request, the Trustee shall authenticate for the Holder at the expense of the Issuers
a new Note (accompanied by a notation of the Guarantees duly endorsed by the
Subsidiary Guarantors) equal in principal amount to the unredeemed portion of
the Note surrendered.

 

Section 3.07.          Optional Redemption.

 

(a)           Except as set forth in clauses (b) and (c) of
this Section 3.07, the Issuers shall not have the option to redeem the
Notes prior to April 15, 2013.  On
or after April 15, 2013, the Issuers shall have the option to redeem all
or, from time to time, a part of the Notes, at the redemption prices (expressed
as percentages of principal amount) set forth below, plus accrued and unpaid
interest (including Additional Interest, if any) to the applicable redemption
date (subject to the rights of Holders of record on the relevant record date to
receive interest due on an Interest Payment Date that is on or prior to the
redemption date), if redeemed during the twelve-month period beginning on April 15
of the years indicated below:

 

	
  YEAR

  	
   

  	
  PERCENTAGE

  	
   

  
	
  2013

  	
   

  	
  104.375

  	
  %

  
	
  2014

  	
   

  	
  102.917

  	
  %

  
	
  2015

  	
   

  	
  101.458

  	
  %

  
	
  2016 and thereafter

  	
   

  	
  100.000

  	
  %

  

 

44

 

(b)           Before April 15,
2013, the Issuers may redeem all or, from time to time, a part of the Notes, at
a redemption price equal to:

(i)            100% of the aggregate
principal amount of the Notes to be redeemed, plus accrued and unpaid interest,
if any, to the applicable redemption date (subject to the right of Holders of
record on the relevant record date to receive interest due on an Interest
Payment Date that is on or prior to the redemption date), plus

 

(ii)           the Make Whole Amount.

 

The Partnership shall calculate such redemption price and set it forth
on an Officers’ Certificate delivered to the Trustee prior to the redemption
date.

 

(c)           Before April 15, 2011, the Issuers may
on any one or more occasions redeem in the aggregate up to 35% of the aggregate
principal amount of Notes issued hereunder with the net cash proceeds of one or
more Equity Offerings at a redemption price equal to 108.750% of the principal
amount of the Notes to be redeemed, plus accrued and unpaid interest, if any,
to the redemption date (subject to the right of Holders of record on a record
date to receive interest due on the relevant Interest Payment Date that is on
or prior to the redemption date); provided that

 

(i)            at least 65% of the
aggregate principal amount of Notes issued hereunder remains outstanding after
each such redemption; and

 

(ii)           any redemption occurs
within 60 days after the closing of such Equity Offering (without regard to any
over-allotment option).

 

(d)           Any redemption pursuant to this Section 3.07
shall be made pursuant to the provisions of Section 3.01 through 3.06
hereof.

 

Section 3.08.          Mandatory Redemption.

 

Except for any repurchase offers
required to be made pursuant to Sections 4.06 and 4.07 hereof, the Issuers
shall not be required to make mandatory redemption payments with respect to the
Notes.

 

Section 3.09.          Offer to Purchase by
Application of Net Proceeds.

 

In the event that, pursuant to Section 4.07
hereof, the Issuers shall be required to commence a pro rata offer (an “Asset
Sale Offer”) to all Holders and all holders of other Indebtedness that is pari
passu with the Notes containing provisions similar to those set forth in this
Indenture with respect to offers to purchase or redeem with the Net Proceeds of
sales of assets to purchase Notes and such other pair passu Indebtedness, it
shall follow the procedures specified below.

 

The Asset Sale Offer shall
remain open for a period of at least 30 days following its commencement but no
longer than 60 days, except to the extent that a longer period is required by
applicable law (the “Offer Period”). 
Promptly after the termination of the Offer Period (the “Purchase Date”),
the Issuers shall purchase the principal amount of Notes required to be

 

45

 

purchased pursuant to Section 4.07 hereof
(the “Offer Amount”) or, if less than the Offer Amount has been tendered, all
Notes tendered and not withdrawn in response to the Asset Sale Offer.  Payment for any Notes so purchased shall be
made in the same manner as interest payments are made.

 

Upon the commencement of an
Asset Sale Offer, the Issuers shall send, by first class mail, a notice to the
Trustee and each of the Holders, with a copy to the Trustee.  The notice shall contain all instructions and
materials necessary to enable such Holders to tender Notes pursuant to the
Asset Sale Offer.  The Asset Sale Offer
shall be made to all Holders.  The
notice, which shall govern the terms of the Asset Sale Offer, shall state:

 

(a)           that the Asset Sale Offer is being made
pursuant to this Section 3.09 and Section 4.07 hereof and the length
of time the Asset Sale Offer shall remain open;

 

(b)           the Offer Amount, the purchase price and the
Purchase Date;

 

(c)           that any Note not validly tendered or
accepted for payment shall continue to accrue interest (including Additional
Interest, if applicable);

 

(d)           that, unless the Issuers default in making
such payment, any Note accepted for payment pursuant to the Asset Sale Offer
shall cease to accrue interest (including Additional Interest, if applicable)
after the Purchase Date;

 

(e)           that Holders electing to have a Note
purchased pursuant to any Asset Sale Offer shall be required to surrender the
Note, with the form entitled “Option of Holder to Elect Purchase” on the
reverse of the Note completed, or transfer by book-entry transfer, to the
Issuers, a depositary, if appointed by the Issuers, or a Paying Agent at the
address specified in the notice at least three days before the Purchase Date;

 

(f)            that Holders shall be entitled to withdraw
their election if the Issuers, the depositary or the Paying Agent, as the case
may be, receives, not later than the expiration of the Offer Period, a
telegram, facsimile transmission or letter setting forth the name of the
Holder, the principal amount of the Note the Holder delivered for purchase and
a statement that such Holder is withdrawing his election to have such Note
purchased;

 

(g)           that, if the aggregate principal amount of
Notes surrendered by Holders exceeds the Offer Amount, the Issuers shall select
the Notes to be purchased on a pro rata basis (with such adjustments as may be
deemed appropriate by the Issuers so that only Notes in minimum denominations
of $2,000 or integral multiples of $1,000 in excess thereof, shall be
purchased); and

 

(h)           that Holders whose Notes were purchased only
in part shall be issued new Notes (accompanied by a notation of the Guarantees
duly endorsed by the Subsidiary Guarantors) equal in principal amount to the
unpurchased portion of the Notes surrendered (or transferred by book-entry
transfer).

 

On the Purchase Date, the
Issuers shall, to the extent lawful, accept for payment, on a pro rata basis to
the extent necessary, the Offer Amount of Notes or portions thereof validly
tendered

 

46

 

and not properly withdrawn pursuant to the
Asset Sale Offer, or if less than the Offer Amount has been validly tendered
and not properly withdrawn, all Notes so tendered and not withdrawn, shall
deposit by 11:00 a.m., New York City time, with the Paying Agent or
depositary an amount equal to the purchase price in respect of all Notes or
portions thereof accepted for payment, and shall deliver to the Trustee an
Officers’ Certificate stating that such Notes or portions thereof were accepted
for payment by the Issuers in accordance with the terms of this Section 3.09.  Upon surrender and cancellation of a
Certificated Note that is purchased in part, the Issuers shall promptly issue
and the Trustee shall authenticate and deliver to the surrendering Holder of
such Certificated Note a new Certificated Note equal in principal amount to the
unpurchased portion of such surrendered Certificated Note; provided that each
such new Certificated Note shall be in a minimum principal amount of $2,000 or
an integral multiple of $1,000 in excess thereof.  Respecting a Global Note that is purchased in
part pursuant to an Asset Sale Offer, the Trustee shall make an endorsement
thereon to reduce the principal amount of such Global Note to an amount equal
to the unpurchased portion of such Global Note, as provided in Section 2.06(h) hereof.  The depositary or the Paying Agent, as the
case may be, shall promptly mail or deliver to each tendering Holder an amount
equal to the purchase price of the Notes tendered by such Holder and accepted
by the Issuers for purchase, and the Issuers shall promptly issue a new Note
(in each case, accompanied by a notation of the Guarantees duly endorsed by the
Subsidiary Guarantors), and the Trustee, upon written request from the Issuers
shall authenticate and mail or deliver such new Note to such Holder, in a
principal amount equal to any unpurchased portion of the Note surrendered.  Any Note not so accepted shall be promptly
mailed or delivered by the Issuers to the Holder thereof.  The Issuers shall publicly announce the
results of the Asset Sale Offer on or as soon as practicable after the Purchase
Date.

 

ARTICLE 4

COVENANTS

Section 4.01.          Payment of Notes.

 

The Issuers shall pay or cause
to be paid the principal of and premium, if any, and interest (including
Additional Interest, if any) on the Notes on the dates and in the manner
provided in the Notes.  Principal, premium,
if any, and interest (including Additional Interest, if any) shall be
considered paid on the date due if the Paying Agent, if other than an Issuer or
any Subsidiary Guarantor thereof, holds as of 11:00 a.m. Eastern Time on
the due date money deposited by the Issuers in immediately available funds and
designated for and sufficient to pay all principal, premium, if any, and
interest (including Additional Interest, if any) then due.  The Issuers shall pay all Additional
Interest, if any, in the same manner on the dates and in the amounts set forth
in the applicable Registration Rights Agreement.

 

The Issuers shall pay interest
(including post-petition interest in any proceeding under any Bankruptcy Law)
on overdue principal and premium at the then applicable interest rate on the
Notes to the extent lawful.  The Issuers
shall pay interest (including post-petition interest in any proceeding under
any Bankruptcy Law) on overdue installments of interest (including Additional
Interest, if any), without regard to any applicable grace period, at the same rate
to the extent lawful.

 

47

 

Section 4.02.          Maintenance of Office or
Agency.

 

The Issuers shall maintain in
the continental United States an office or agency (which may be an office of
the Trustee or an Affiliate of the Trustee, Registrar or co-registrar), where
Notes may be surrendered or presented for payment, where Notes may be
surrendered for registration of transfer or for exchange and where notices and
demands to or upon the Issuers or the Subsidiary Guarantors in respect of the
Notes and this Indenture may be served. 
The Issuers shall give prompt written notice to the Trustee of the
location, and any change in the location, of such office or agency.  If at any time the Issuers shall fail to
maintain any such required office or agency or shall fail to furnish the
Trustee with the address thereof, such presentations, surrenders, notices and
demands may be made or served at the Corporate Trust Office of the Trustee.

 

The Issuers may also from time
to time designate one or more other offices or agencies where the Notes may be
presented or surrendered for any or all such purposes and may from time to time
rescind such designations.  The Issuers
shall give prompt written notice to the Trustee of any such designation or
rescission and of any change in location of any such other office or agency.

 

The Issuers hereby designate the
Corporate Trust Office of the Trustee as one such office or agency of the
Issuers in accordance with Section 2.03.

 

Section 4.03.          Compliance Certificate.

 

(a)           The Issuers and the Subsidiary Guarantors
shall deliver to the Trustee, within 90 days after the end of each fiscal year,
an Officers’ Certificate stating that a review of the activities of the Issuers
and the Restricted Subsidiaries of the Partnership during the preceding fiscal
year has been made under the supervision of the signing Officers with a view to
determining whether the Issuers and the Subsidiary Guarantors have kept,
observed, performed and fulfilled their respective obligations under this
Indenture and the Guarantees, respectively, and further stating, as to each
such Officer signing such certificate, that to the best of his or her knowledge
each of such Issuers and such Subsidiary Guarantors, as the case may be, has kept,
observed, performed and fulfilled each and every covenant contained in this
Indenture and is not in default in the performance or observance of any of the
terms, provisions and conditions of this Indenture (or, if a Default or Event
of Default shall have occurred and be continuing, describing all such Defaults
or Events of Default of which he or she may have knowledge and what action such
Issuer or such Subsidiary Guarantor, as the case may be, is taking or proposes
to take with respect thereto).

 

(b)           [Intentionally omitted]
..

 

(c)           Each of the Issuers shall, so long as any of
the Notes are outstanding, deliver to the Trustee, forthwith upon any Officer
of the General Partner or MarkWest Finance becoming aware of any Default or
Event of Default, an Officers’ Certificate specifying such Default or Event of
Default and what action the Issuers are taking or propose to take with respect
thereto.

 

48

 

Section 4.04.          Taxes.

 

The Issuers shall pay, and shall
cause each of its Restricted Subsidiaries to pay, prior to delinquency, all
material taxes, assessments, and governmental levies except such as are
contested in good faith and by appropriate proceedings or where the failure to
effect such payment is not adverse in any material respect to the Holders of
the Notes.

 

Section 4.05.          Stay, Extension and Usury Laws.

 

Each of the Issuers and the
Subsidiary Guarantors covenants (to the extent that it may lawfully do so) that
it shall not at any time insist upon, plead, or in any manner whatsoever claim
or take the benefit or advantage of, any stay, extension or usury law wherever
enacted, now or at any time hereafter in force, that may affect the covenants
or the performance of this Indenture; and each of the Issuers and the
Subsidiary Guarantors (to the extent that it may lawfully do so) hereby
expressly waives all benefit or advantage of any such law, and covenants that
it shall not, by resort to any such law, hinder, delay or impede the execution
of any power herein granted to the Trustee, but shall suffer and permit the
execution of every such power as though no such law has been enacted.

 

Section 4.06.          Change of Control.

 

(a)           If a Change of Control occurs, each Holder
of Notes shall have the right to require the Issuers to repurchase all or any
part (equal to $2,000 or an integral multiple of $1,000 in excess thereof) of
that Holder’s Notes pursuant to the offer described below (the “Change of
Control Offer”).  In the Change of
Control Offer, the Issuers shall offer a “Change of Control Payment” in cash
equal to 101% of the aggregate principal amount of Notes repurchased, plus
accrued and unpaid interest (including Additional Interest, if any) thereon, if
any, to the date of purchase (the “Change of Control Payment”), subject to the
rights of any Holder in whose name a Note is registered on a record date
occurring prior to the Change of Control Payment Date to receive interest due
on an Interest Payment Date that is on or prior to such Change of Control
Payment Date.  Within 30 days following
any Change of Control, the Issuers shall mail a notice to each Holder
describing the transaction or transactions that constitute the Change of
Control and offering to repurchase Notes on the Change of Control Payment Date
specified in such notice, pursuant to the procedures required by this Indenture
and described in such notice.  The
Issuers shall comply with the requirements of Rule 14e-l under the
Exchange Act and any other securities laws and regulations thereunder to the
extent such laws and regulations are applicable in connection with the
repurchase of the Notes as a result of a Change of Control.  To the extent that the provisions of any
securities laws or regulations conflict with the provisions of this Section 4.06,
the Issuers shall comply with the applicable securities laws and regulations
and shall not be deemed to have breached their obligations under this Section 4.06
by virtue of such conflict.

 

(b)           Within 30 days following any Change of
Control, the Issuers shall mail by first class mail, a notice to each Holder,
with a copy of such notice to the Trustee. 
The notice, which shall govern the terms of the Change of Control Offer,
shall state, among other things:

 

49

 

(i)            that a Change of
Control has occurred and a Change of Control Offer is being made as provided
for herein, and that, although Holders are not required to tender their Notes,
all Notes that are validly tendered shall be accepted for payment;

 

(ii)           the Change of Control
Payment and the Change of Control Payment Date, which will be no earlier than
30 days and no later than 60 days after the date such notice is mailed (the “Change
of Control Payment Date”);

 

(iii)          that any Note accepted
for payment pursuant to the Change of Control Offer (and duly paid for on the
Change of Control Payment Date) shall cease to accrue interest (including
Additional Interest, if applicable) after the Change of Control Payment Date;

 

(iv)          that any Notes (or
portions thereof) not validly tendered shall continue to accrue interest
(including Additional Interest, if applicable);

 

(v)           that any Holder
electing to have a Note purchased pursuant to any Change of Control Offer shall
be required to surrender the Note, with the form entitled “Option of Holder to
Elect Purchase” on the reverse of the Note completed, or transfer by book-entry
transfer, to the Issuers, a depositary, if appointed by the Issuers, or a
Paying Agent at the address specified in the notice at least one (1) Business
Day before the Change of Control Payment Date;

 

(vi)          that Holders shall be
entitled to withdraw their election if the Issuers, the depositary or the
Paying Agent, as the case may be, receives, not later than the expiration of
the Change of Control Offer, a telegram, facsimile transmission or letter
setting forth the name of the Holder, the principal amount of the Note the
Holder delivered for purchase and a statement that such Holder is withdrawing
his election to have such Note purchased; and

 

(vii)         the instructions and any
other information necessary to enable Holders to tender their Notes (or
portions thereof) and have such Notes (or portions thereof) purchased pursuant
to the Change of Control Offer.

 

(c)           On the Change of
Control Payment Date, the Issuers shall, to the extent lawful:

 

(i)            accept for payment all
Notes or portions thereof properly tendered and not withdrawn pursuant to the
Change of Control Offer;

 

(ii)           deposit by 11:00 a.m.,
New York City time, with the Paying Agent or depositary an amount equal to the
Change of Control Payment in respect of all Notes or portions thereof so
tendered; and

 

(iii)          deliver or cause to be
delivered to the Trustee for cancellation the Notes so accepted together with
an Officers’ Certificate stating the aggregate principal amount of Notes or
portions thereof being purchased by the Issuers.

 

50

 

(d)           The depositary or the Paying Agent shall
promptly mail to each Holder of Notes so tendered the Change of Control Payment
for such Notes (or, if all the Notes are then in global form, make such payment
through the facilities of DTC), and the Issuers shall promptly issue a new Note
(in each case, accompanied by a notation of the Guarantees duly endorsed by the
Subsidiary Guarantors), and the Trustee, upon written request from the Issuers,
shall authenticate and mail (or cause to be transferred by book entry) to each
Holder such new Note equal in principal amount to any unpurchased portion of
the Notes surrendered; provided that each such new Note shall be in a principal
amount of $2,000 or an integral multiple of $1,000 in excess thereof.  The Issuers shall publicly announce the
results of the Change of Control Offer on or as soon as practicable after the
Change of Control Payment Date.

 

(e)           The provisions described in this Section 4.06
that require the Issuers to make a Change of Control Offer following a Change
of Control shall be applicable regardless of whether or not any other
provisions of this Indenture are applicable.

 

(f)            Notwithstanding the other provisions of
this Section 4.06, the Issuers shall not be required to make a Change of
Control Offer upon a Change of Control, and a Holder will not have the right to
require that the Issuers repurchase any Notes pursuant to a Change of Control
Offer, if a third party makes the Change of Control Offer in the manner, at the
times and otherwise in compliance with the requirements set forth in this
Indenture applicable to a Change of Control Offer made by the Issuers and
purchases all Notes validly tendered and not withdrawn under such Change of
Control Offer.

 

Section 4.07.          Asset Sales.

 

(a)           The Partnership shall
not, and shall not permit any of its Restricted Subsidiaries to, consummate an
Asset Sale unless:

(i)            the Partnership (or
the Restricted Subsidiary, as the case may be) receives consideration at the
time of such Asset Sale at least equal to the fair market value of the assets
or Equity Interests issued or sold or otherwise disposed of;

 

(ii)           such fair market value
is determined by (a) an executive officer of the General Partner if the
value is less than $10.0 million, as evidenced by an Officers’ Certificate
delivered to the Trustee or (b) the Board of Directors of the General
Partner if the value is $10.0 million or more, as evidenced by a resolution of
such Board of Directors of the General Partner; and

 

(iii)          at least 75% of the
aggregate consideration received by the Partnership and its Restricted
Subsidiaries in the Asset Sale and all other Asset Sales of the Partnership and
its Restricted Subsidiaries since the Issue Date is in the form of cash or Cash
Equivalents.  For purposes of this clause
(iii), each of the following shall be deemed to be cash:

 

(A)          any liabilities (as
shown on such Issuer’s or such Restricted Subsidiary’s most recent balance
sheet) of the Partnership or any Restricted Subsidiary (other than contingent
liabilities and liabilities that are by their terms subordinated to the Notes
or any Guarantee) that are assumed by the transferee of

 

51

 

any such assets pursuant to a
customary novation agreement that releases the Partnership or such Restricted
Subsidiary from further liability; and

 

(B)           any securities, notes
or other Obligations received by the Partnership or any such Restricted
Subsidiary from such transferee that are within 90 days after the Asset Sale
(subject to ordinary settlement periods) converted by such Issuer or such
Restricted Subsidiary into cash (to the extent of the cash received in that
conversion).

 

(b)           Within 360 days after the receipt of any Net
Proceeds from an Asset Sale, the Partnership or a Restricted Subsidiary may
apply (or enter into a definitive agreement for such application, provided that
such application occurs within 90 days after the end of such 360-day period)
such Net Proceeds at its option:

 

(i)            to repay senior
Indebtedness of the Partnership and/or its Restricted Subsidiaries (or to make
an offer to repurchase or redeem any such Indebtedness, provided that such
repurchase or redemption closes within 45 days after the end of such 360-day
period);

 

(ii)           to make a capital
expenditure in a Permitted Business;

 

(iii)          to acquire other
long-term tangible assets that are used or useful in a Permitted Business; or

 

(iv)          to invest in any other
Permitted Business Investment or any other Permitted Investments other than
Investments in Cash Equivalents, Interest Swaps or Currency Agreements.

 

Pending the final application of any such Net
Proceeds, the Partnership or a Restricted Subsidiary may temporarily reduce
revolving credit borrowings or otherwise invest such Net Proceeds in any manner
that is not prohibited by this Indenture.

 

(c)           Any Net Proceeds from Asset Sales that are
not applied or invested as provided in Section 4.07(b) above will
constitute “Excess Proceeds.”  When the
aggregate amount of Excess Proceeds exceeds $20.0 million, the Issuers will
make an Asset Sale Offer to all Holders of Notes and all holders of other
Indebtedness that is pari passu with the Notes containing provisions similar to
those set forth in this Indenture with respect to offers to purchase or redeem
with the proceeds of sales of assets to purchase the maximum principal amount
of Notes and such other pari passu Indebtedness that may be purchased out of
the Excess Proceeds.  The offer price in
any Asset Sale Offer will be equal to 100% of principal amount plus accrued and
unpaid interest (including any Additional Interest in the case of the Notes),
if any, to the Purchase Date, subject to the rights of any Holder in whose name
a Note is registered on a record date occurring prior to the Purchase Date to
receive interest on an Interest Payment Date that is on or prior to the
Purchase Date, and will be payable in cash. 
If any Excess Proceeds remain after consummation of an Asset Sale Offer,
the Partnership may use such Excess Proceeds for any purpose not otherwise
prohibited by this Indenture, including, without limitation, the repurchase or
redemption of Indebtedness of the Issuers or any Subsidiary Guarantor that is
subordinated to the Notes or, in the case of any Subsidiary Guarantor, the
Guarantee of such Subsidiary

 

52

 

Guarantor. 
If the aggregate principal amount of Notes tendered into such Asset Sale
Offer exceeds the amount of Excess Proceeds allocated for repurchases of Notes
pursuant to the Asset Sale Offer for Notes, the Trustee shall select the Notes
to be purchased on a pro rata basis. 
Upon completion of each Asset Sale Offer, the amount of Excess Proceeds
shall be reset at zero.

 

(d)           The Partnership shall comply with the
requirements of Rule 14e-1 under the Exchange Act and any other securities
laws and regulations thereunder to the extent those laws and regulations are
applicable in connection with each repurchase of Notes pursuant to an Asset
Sale Offer.  To the extent that the
provisions of any securities laws or regulations conflict with Section 3.09
or this Section 4.07, the Partnership shall comply with the applicable
securities laws and regulations and shall not be deemed to have breached its
obligations under Section 3.09 or this Section 4.07 by virtue of such
conflict.

 

Section 4.08.          Restricted Payments.

 

(a)           The Partnership shall
not, and shall not permit any of its Restricted Subsidiaries to, directly or
indirectly:

 

(i)            declare or pay any
dividend or make any other payment or distribution on account of the Equity
Interests of the Partnership or of any of its Restricted Subsidiaries
(including, without limitation, any payment in connection with any merger or
consolidation involving the Partnership or any of its Restricted Subsidiaries)
or to the direct or indirect holders of the Equity Interests of the Partnership
or of any of its Restricted Subsidiaries in their capacity as such (other than
dividends or distributions payable in Equity Interests of the Partnership
(other than Disqualified Equity) and other than dividends or distributions
payable to the Partnership or a Restricted Subsidiary of the Partnership).

 

(ii)           purchase, redeem or
otherwise acquire or retire for value (including, without limitation, in
connection with any merger or consolidation involving an Issuer) any Equity
Interests of the Partnership or of any of its Restricted Subsidiaries (other
than any such Equity Interests owned by the Partnership or any of its
Restricted Subsidiaries);

 

(iii)          make any payment on or
with respect to, or purchase, redeem, defease or otherwise acquire or retire
for value any Subordinated Obligation or Guarantor Subordinated Obligation,
except a payment of interest or principal at the Stated Maturity thereof;

 

(iv)          make any Investment
other than a Permitted Investment or a Permitted Business Investment (all such
payments and other actions set forth in clauses (i) through (iv) above
being collectively referred to as “Restricted Payments”),

unless, at the time of and after giving effect
to such Restricted Payment, no Default (except a Reporting Default) or Event of
Default shall have occurred and be continuing or would occur as a consequence
thereof and either:

 

(A)          if the Fixed Charge
Coverage Ratio for the Partnership’s four most recent fiscal quarters for which
internal financial statements are available is not

 

53

 

less than 1.75 to 1.0, such
Restricted Payment, together with the aggregate amount of all other Restricted
Payments made by the Partnership and its Restricted Subsidiaries during the
quarter in which such Restricted Payment is made, is less than the sum, without
duplication, of

 

(i)            Available Cash from
Operating Surplus as of the end of the immediately preceding quarter, plus

 

(ii)           the sum of (1) the
aggregate net cash proceeds of any (i) substantially concurrent capital
contribution to the Partnership from any Person (other than to a Restricted
Subsidiary of the Partnership) made after the Issue Date or (ii) substantially
concurrent issuance and sale (other than to a Restricted Subsidiary of the
Partnership) made after the Issue Date of Equity Interests (other than
Disqualified Equity) of the Partnership or from the issuance or sale (other
than to a Restricted Subsidiary of the Partnership) made after the Issue Date
of convertible or exchangeable Disqualified Equity or convertible or
exchangeable debt securities of the Partnership that have been converted into
or exchanged for such Equity Interests (other than Disqualified Equity), and (2) the
fair market value of any Permitted Business or long-term tangible assets that
are useful in a Permitted Business to the extent acquired in consideration of
Equity Interests of the Partnership (other than Disqualified Equity) since the
Issue Date, plus

 

(iii)          to the extent that any
Restricted Investment that was made after the Issue Date is sold for cash or
Cash Equivalents or otherwise liquidated or repaid for cash or Cash
Equivalents, the lesser of the refund of capital or similar payment made in
cash or Cash Equivalents with respect to such Restricted Investment (less the
cost of such disposition, if any) and the initial amount of such Restricted
Investment (other than to a Restricted Subsidiary of the Partnership), plus

 

(iv)          the net reduction in
Restricted Investments resulting from dividends, repayments of loans or
advances, or other transfers of assets in each case to the Partnership or any
of its Restricted Subsidiaries from any Person (including, without limitation,
Unrestricted Subsidiaries) or from redesignations of Unrestricted Subsidiaries
as Restricted Subsidiaries, to the extent such amounts have not been included
in Available Cash from Operating Surplus for any period commencing on or after
the Issue Date (items (ii), (iii) and (iv) of this clause (A) being
referred to as “Incremental Funds”), minus

 

(v)           the aggregate amount of
Incremental Funds previously expended pursuant to this clause (A) or
clause (B) below; or

 

(B)           if the Fixed Charge
Coverage Ratio for the Partnership’s four most recent fiscal quarters for which
internal financial statements are available is less

 

54

 

than 1.75 to 1.0, such
Restricted Payment, together with the aggregate amount of all other Restricted
Payments made by the Partnership and its Restricted Subsidiaries during the
quarter in which such Restricted Payment is made (such Restricted Payments for
purposes of this clause (B) meaning only distributions on common units of
the Partnership, plus the related distribution on the general partner
interest), is less than the sum, without duplication, of:

 

(i)            $50.0 million less the
aggregate amount of all prior Restricted Payments made by the Partnership and
its Restricted Subsidiaries pursuant to this clause (B)(i) since the Issue
Date, plus

 

(ii)           Incremental Funds to
the extent not previously expended pursuant to this clause (B) or clause (A) above.

 

For purposes of clauses (A) and (B) above,
the term “substantially concurrent” means that either (x) the offering was
consummated within 120 days of the date of determination or (y) the
offering was consummated within 24 months of the date of determination and the
proceeds therefrom were used for the purposes expressly stated in the documents
related thereto and may be traced to such use by segregating, separating or
otherwise specifically identifying the movement of such proceeds.

 

(b)           So long as no Default
(except a Reporting Default) has occurred and is continuing or would be caused
thereby (except with respect to clause (i) below under which the payment
of a distribution or dividend is permitted), the preceding provisions of this Section 4.08
shall not prohibit:

 

(i)            the payment by the
Partnership or any of its Restricted Subsidiaries of any distribution or
dividend within 60 days after the date of declaration thereof, if at said date
of declaration such payment would have complied with the provisions of this
Indenture;

 

(ii)           the redemption,
repurchase, retirement, defeasance or other acquisition of any Subordinated
Obligation or any Guarantor Subordinated Obligation or of any Equity Interests
of the Partnership in exchange for, or out of the net cash proceeds of, a
substantially concurrent (a) capital contribution to the Partnership from
any Person (other than a Restricted Subsidiary of the Partnership) or (b) sale
(other than to a Restricted Subsidiary of the Partnership) of Equity Interests
(other than Disqualified Equity) of the Partnership (a sale will be deemed
substantially concurrent if such redemption, repurchase, retirement, defeasance
or other acquisition occurs not more than 120 days after such sale); provided
that the amount of any such net cash proceeds that are utilized for any such
redemption, repurchase, retirement, defeasance or other acquisition shall be
excluded or deducted from the calculation of Available Cash from Operating
Surplus and Incremental Funds;

 

(iii)          the redemption,
repurchase, retirement, defeasance or other acquisition of any Subordinated
Obligation or Guarantor Subordinated Obligation with the net cash proceeds from
an incurrence of, or in exchange for, Permitted Refinancing Indebtedness;

 

55

 

(iv)          the payment of any distribution
or dividend by a Restricted Subsidiary to the Partnership or to the holders of
the Equity Interests (other than Disqualified Equity) of such Restricted
Subsidiary on a pro rata basis; and

 

(v)           the repurchase,
redemption or other acquisition or retirement for value of any Equity Interests
of the Partnership or of any of its Restricted Subsidiaries pursuant to any
management equity subscription agreement or equity option agreement or other
employee benefit plan or to satisfy obligations under any Equity Interests
appreciation rights or option plan or similar arrangement; provided that the
aggregate price paid for all such repurchased, redeemed, acquired or retired
Equity Interests shall not exceed $3.0 million in any calendar year.

 

In computing the amount of
Restricted Payments previously made for purposes of Section 4.08(a),
Restricted Payments made under clauses (i) (but only if the declaration of
such dividend or other distribution has not been counted in a prior period)
and, to the extent of amounts paid to holders other than the Partnership or any
of its Restricted Subsidiaries, (iv) of this Section 4.08(b) shall
be included, and Restricted Payments made under clauses (ii), (iii) and (v) and,
except to the extent noted above, (iv) of this Section 4.08(b) shall
not be included.  The amount of all
Restricted Payments (other than cash) shall be the fair market value on the
date of the Restricted Payment of the asset(s) or securities proposed to
be transferred or issued by the Partnership or such Restricted Subsidiary, as
the case may be, pursuant to the Restricted Payment.  The fair market value of any assets or
securities that are required to be valued by this Section 4.08 shall be
determined, in the case of amounts under $10.0 million, by an officer of the
General Partner and, in the case of amounts over $10.0 million, by the Board of
Directors of the General Partner whose resolution with respect thereto shall be
delivered to the Trustee.

 

Section 4.09.          Incurrence of
Indebtedness and Issuance of Disqualified Equity.

 

(a)           The Partnership shall not, and shall not
permit any of its Restricted Subsidiaries to, directly or indirectly, create,
incur, issue, assume, guarantee or otherwise become directly or indirectly
liable, contingently or otherwise, with respect to (collectively, “incur”) any
Indebtedness (including Acquired Debt), and the Partnership will not issue any
Disqualified Equity and will not permit any of its Restricted Subsidiaries to
issue any Disqualified Equity; provided, however, that the Partnership and any
Restricted Subsidiary may incur Indebtedness (including Acquired Debt), and the
Partnership and the Restricted Subsidiaries may issue Disqualified Equity, if
the Fixed Charge Coverage Ratio for the Partnership’s most recently ended four
full fiscal quarters for which internal financial statements are available
immediately preceding the date on which such additional Indebtedness is
incurred or such Disqualified Equity is issued would have been at least 2.0 to
1.0, determined on a pro forma basis (including a pro forma application of the
net proceeds therefrom), as if the additional Indebtedness had been incurred,
or the Disqualified Equity had been issued, as the case may be, at the
beginning of such four-quarter period.

 

(b)           Notwithstanding the
prohibitions of Section 4.09(a), so long as no Default or Event of Default
shall have occurred and be continuing or would be caused thereby, the
Partnership and its Restricted Subsidiaries may incur any of the following
items of Indebtedness (collectively, “Permitted Debt”):

 

56

 

(i)            the incurrence by the
Partnership and any Restricted Subsidiary of Indebtedness under Credit
Facilities and the guarantees thereof; provided that the aggregate principal
amount of all Indebtedness of the Partnership and the Restricted Subsidiaries
incurred pursuant to this clause (i) and outstanding under all Credit
Facilities after giving effect to such incurrence does not exceed the greater
of (A) $500.0 million or (B) $300.0 million plus 15% of the
Consolidated Net Tangible Assets of the Partnership;

 

(ii)           the incurrence by the
Partnership and its Restricted Subsidiaries of Existing Indebtedness (other
than under the Credit Facilities);

 

(iii)          the incurrence by the
Partnership and the Subsidiary Guarantors of Indebtedness represented by the
Notes issued and sold in the Offering, any Exchange Notes and the Guarantees
and the related Obligations;

 

(iv)          the incurrence by the
Partnership or any of its Restricted Subsidiaries of Indebtedness represented
by Capital Lease Obligations, mortgage financings or purchase money
obligations, in each case, incurred for the purpose of financing all or any
part of the purchase price or cost of construction or improvement of property,
plant or equipment used in the business of the Partnership or such Restricted
Subsidiary, including all Permitted Refinancing Indebtedness incurred to
extend, refinance, renew, replace, defease or refund any Indebtedness incurred
pursuant to this clause (iv), provided that after giving effect to any such
incurrence, the principal amount of all Indebtedness incurred pursuant to this
clause (iv) and then outstanding shall not exceed the greater of (a) $25.0
million or (b) 2.5% of the Consolidated Net Tangible Assets of the
Partnership at such time;

 

(v)           the incurrence by the
Partnership or any of its Restricted Subsidiaries of Permitted Refinancing
Indebtedness in exchange for, or the net proceeds of which are used to extend,
refinance, renew, replace, defease or refund, Indebtedness that was permitted
by this Indenture to be incurred under Section 4.09(a) or clause (ii) or
(iii) of this Section 4.09(b) or this clause (v);

 

(vi)          the incurrence by the
Partnership or any of its Restricted Subsidiaries of intercompany Indebtedness
between or among the Partnership and any of its Restricted Subsidiaries;
provided, however, that:

 

(A)          if the Partnership is
the obligor on such Indebtedness and a Subsidiary Guarantor is not the obligee,
such Indebtedness must be expressly subordinated to the prior payment in full
in cash of all Obligations with respect to the Notes, or if a Subsidiary
Guarantor is the obligor on such Indebtedness and neither the Partnership nor
another Subsidiary Guarantor is the obligee, such Indebtedness must be
expressly subordinated to the prior payment in full in cash of all Obligations
with respect to the Guarantee of such Subsidiary Guarantor; and

 

(B)           (i) any subsequent
issuance or transfer of Equity Interests that results in any such Indebtedness
being held by a Person other than the Partnership or a Restricted Subsidiary
thereof and (ii) any sale or other transfer of any such

 

57

 

Indebtedness to a Person that
is neither the Partnership nor a Restricted Subsidiary thereof, shall be
deemed, in each case, to constitute an incurrence of such Indebtedness by the
Partnership or such Restricted Subsidiary, as the case may be, that was not
permitted by this clause (vi);

 

(vii) the
incurrence by the Partnership or any of its Restricted Subsidiaries of Hedging
Obligations that are incurred for the purpose of fixing or hedging (but not for
speculative purposes) (A) foreign currency exchange rate risks of the
Partnership or any Restricted Subsidiary, (B) interest rate risks with
respect to any floating rate Indebtedness of the Partnership or any Restricted
Subsidiary that is permitted by the terms of this Indenture to be outstanding
or (C) commodities pricing risks of the Partnership or any Restricted
Subsidiary in respect of Hydrocarbons used, produced, processed or sold by the
Partnership or any of its Restricted Subsidiaries;

 

(viii) the
guarantee by the Partnership or any of its Restricted Subsidiaries of
Indebtedness of the Partnership or any of its Restricted Subsidiaries that was
permitted to be incurred by another provision of this Section 4.09;
provided, that in the event such Indebtedness that is being guaranteed is a
Subordinated Obligation or a Guarantor Subordinated Obligation, then the
guarantee shall be subordinated in right of payment to the Notes or the
Guarantee, as the case may be;

 

(ix) bid,
performance, surety and appeal bonds incurred in the ordinary course of
business, including guarantees and obligations respecting standby letters of
credit supporting such obligations, to the extent not drawn (in each case other
than an obligation for money borrowed);

 

(x) the
incurrence by the Partnership or any of its Restricted Subsidiaries of Acquired
Debt in connection with a merger or consolidation meeting either one of the
financial tests set forth in clause (iv) of Section 5.01(a); and

 

(xi) the
incurrence by the Partnership or any of its Restricted Subsidiaries of
additional Indebtedness in an aggregate principal amount at any time
outstanding not to exceed the greater of (a) $45.0 million or (b) 4.0%
of the Consolidated Net Tangible Assets of the Partnership.

 

(c)           For purposes of determining compliance with
this Section 4.09, in the event that an item of proposed Indebtedness
meets the criteria of more than one of the categories of Permitted Debt
described in paragraphs (b)(i) through (b)(xi) above, or is entitled to be
incurred pursuant to Section 4.09(a), the Partnership shall be permitted
to classify (or later reclassify in whole or in part) such item of Indebtedness
on the date of its incurrence in any manner that complies with this Section 4.09.  An item of Indebtedness may be divided and
classified in one or more of the types of Permitted Indebtedness.  Any Indebtedness under Credit Facilities on
the Issue Date shall be considered incurred under Section 4.09(a).

 

(d)           The accrual of interest, the accretion or
amortization of original issue discount, the payment of interest on any
Indebtedness in the form of additional Indebtedness with the same terms, and
the payment of dividends on Disqualified Equity in the form of additional
shares of

 

58

 

the same class of Disqualified Equity shall
not be deemed to be an incurrence of Indebtedness or an issuance of Disqualified
Equity for purposes of this Section 4.09; provided, in each such case,
that the amount thereof is included in Fixed Charges of the Partnership as
accrued.

 

Section 4.10.          Liens.

 

The Partnership shall not, and
shall not permit any of its Restricted Subsidiaries to create, incur, assume or
suffer to exist any Lien of any kind securing Indebtedness upon any asset now
owned or hereafter acquired, except Permitted Liens, without making effective
provision whereby all Obligations due under the Notes and this Indenture or any
Guarantee, as applicable, will be secured by a Lien equally and ratably with
(or prior to in the case of Liens with respect to Subordinated Obligations or
Guarantor Subordinated Obligations, as the case may be) any and all Obligations
thereby secured for so long as any such Obligations shall be so secured.

 

Section 4.11.          Dividend and Other
Payment Restrictions Affecting Subsidiaries.

 

(a)           The Partnership shall
not, and shall not permit any of its Restricted Subsidiaries to, directly or
indirectly, create or permit to exist or become effective any encumbrance or
restriction on the ability of any Restricted Subsidiary to:

 

(i)            pay dividends or make
any other distributions on its Equity Interests to the Partnership or any of
the Partnership’s Restricted Subsidiaries, or pay any indebtedness or other
obligations owed to the Partnership or any of the other Restricted
Subsidiaries;

 

(ii)           make loans or advances
to or make other Investments in the Partnership or any of the other Restricted
Subsidiaries; or

 

(iii)          transfer any of its
properties or assets to the Partnership or any of the other Restricted
Subsidiaries.

 

(b)           The restrictions
contained in Section 4.11(a) shall not apply to encumbrances or
restrictions existing under or by reason of:

 

(i)            agreements as in
effect on the Issue Date and any amendments, modifications, restatements,
renewals, increases, supplements, refundings, replacements or refinancings of
any such agreements or any Existing Indebtedness to which such agreement
relates, provided that such amendments, modifications, restatements, renewals,
increases, supplements, refundings, replacements or refinancings are no more
restrictive, taken as a whole, with respect to such distribution, dividend and
other payment restrictions and loan or investment restrictions than those
contained in such agreement, as in effect on the Issue Date;

 

(ii)           this Indenture, the
Notes and the Guarantees;

 

(iii)          applicable law;

 

(iv)          any instrument governing
Indebtedness or Equity Interests of a Person acquired by the Partnership or any
of its Restricted Subsidiaries as in effect at the time of

 

59

 

such acquisition (except to the
extent such Indebtedness was incurred in connection with or in contemplation of
such acquisition), which encumbrance or restriction is not applicable to any
Person, or the property or assets of any Person, other than such Person, or the
property or assets of such Person, so acquired, provided that, in the case of
Indebtedness, such Indebtedness was permitted by the terms of this Indenture to
be incurred;

 

(v)           customary
non-assignment provisions in Hydrocarbon purchase and sale or exchange
agreements or similar operational agreements or in licenses and leases entered
in the ordinary course of business and consistent with past practices;

 

(vi)          Capital Lease
Obligations, mortgage financings or purchase money obligations, in each case
for property acquired in the ordinary course of business that impose
restrictions on the property so acquired of the nature described in clause (iii) of
Section 4.11(a);

 

(vii)         any agreement for the
sale or other disposition of a Restricted Subsidiary that restricts
distributions by that Restricted Subsidiary pending its sale or other
disposition;

 

(viii)        Permitted Refinancing
Indebtedness, provided that the restrictions contained in the agreements
governing such Permitted Refinancing Indebtedness are no more restrictive,
taken as a whole, than those contained in the agreements governing the
Indebtedness being refinanced;

 

(ix)           Liens securing
Indebtedness otherwise permitted to be incurred pursuant to the provisions of Section 4.10
that limit the right of the Partnership or any of its Restricted Subsidiaries
to dispose of the assets subject to such Lien;

 

(x)            provisions with
respect to the disposition or distribution of assets or property in joint
venture agreements, asset sale agreements, stock sale agreements and other
similar agreements entered into in the ordinary course of business;

 

(xi)           any agreement or
instrument relating to any property or assets acquired after the Issue Date, so
long as such encumbrance or restriction relates only to the property or assets
so acquired and is not and was not created in anticipation of such
acquisitions; and

 

(xii)          restrictions on cash or
other deposits or net worth imposed by customers under contracts entered into
in the ordinary course of business.

 

Section 4.12.          Transactions With
Affiliates.

 

(a)           The Partnership shall not, and shall not
permit any of its Restricted Subsidiaries to, make any payment to, or sell,
lease, transfer or otherwise dispose of any of its properties or assets to, or
purchase any property or assets from, or enter into or make or amend any
transaction, contract, agreement, understanding, loan, advance or guarantee
with, or for the benefit of, any Affiliate (each, an “Affiliate Transaction”),
unless:

 

60

 

(i)            such Affiliate
Transaction is on terms that are no less favorable to the Partnership or the
relevant Restricted Subsidiary than those that would have been obtained in a
comparable transaction by the Partnership or such Restricted Subsidiary with an
unrelated Person; and

 

(ii)           the Partnership
delivers to the Trustee:

 

(A)          with respect to any
Affiliate Transaction or series of related Affiliate Transactions involving
aggregate consideration in excess of $10.0 million but less than or equal to
$25.0 million, an Officers’ Certificate certifying that such Affiliate
Transaction complies with this Section 4.12 and that such Affiliate
Transaction has been approved by a majority of the disinterested members of the
Board of Directors of the General Partner; and

 

(B)           with respect to any
Affiliate Transaction or series of related Affiliate Transactions involving
aggregate consideration in excess of $25.0  million,
(i) a resolution of the Board of Directors of the General Partner set
forth in an Officers’ Certificate certifying that such Affiliate Transaction
complies with this Section 4.12 and that such Affiliate Transaction has
been approved by a majority of the disinterested members of the Board of
Directors of the General Partner and (ii) an opinion as to the fairness to
the Partnership of such Affiliate Transaction from a financial point of view
issued by an accounting, appraisal or investment banking firm of national
standing.

 

(b)           The following items
shall not be deemed to be Affiliate Transactions and, therefore, shall not be
subject to the provisions of Section 4.11(a):

 

(i)            any employment, equity
option or equity appreciation agreement or plan entered into by the Partnership
or any of its Restricted Subsidiaries in the ordinary course of business;

 

(ii)           transactions between or
among the Partnership and/or its Restricted Subsidiaries;

 

(iii)          Restricted Payments that
are permitted by Section 4.08;

 

(iv)          customary compensation,
indemnification and other benefits made available to officers, directors or
employees of the Partnership or a Restricted Subsidiary, including
reimbursement or advancement of out-of-pocket expenses and provisions of
officers’ and directors’ liability insurance; and

 

(v)           sales of Equity
Interests (other than Disqualified Equity) to Affiliates of the Partnership.

 

Section 4.13.          Additional Subsidiary
Guarantees.

 

If, after the Issue Date, any
Restricted Subsidiary of the Partnership that is not already a Subsidiary
Guarantor guarantees any other Indebtedness of either of the Issuers or any

 

61

 

Indebtedness of the Operating Company, or if
the Operating Company, if not then a Subsidiary Guarantor, guarantees any other
Indebtedness of either of the Issuers or incurs any Indebtedness under any
Credit Facility, then in either case such Subsidiary must become a Subsidiary
Guarantor by executing a supplemental indenture substantially in the form of
Annex A hereto and delivering an Opinion of Counsel and Officers’
Certificate to the Trustee pursuant to Section 9.06 within 10 Business
Days of the date on which it guaranteed or incurred such Indebtedness.  Notwithstanding the preceding, any Guarantee
of a Restricted Subsidiary that was incurred pursuant to this Section 4.13
shall be released in accordance with the terms and subject to the conditions of
Section 10.05.

 

Section 4.14.          Designation of
Restricted and Unrestricted Subsidiaries.

 

(a)           The Board of Directors of the General
Partner may designate any Restricted Subsidiary of the Partnership to be an
Unrestricted Subsidiary if that designation would not cause a Default or Event
of Default.  If a Restricted Subsidiary
is designated as an Unrestricted Subsidiary, all outstanding Investments owned
by the Partnership and its Restricted Subsidiaries in the Subsidiary so
designated will be deemed to be an Investment made as of the time of such
designation and will reduce the amount available for Restricted Payments under Section 4.08(a),
or represent Permitted Investments or Permitted Business Investments, as
applicable.  All such outstanding
Investments will be valued at their fair market value at the time of such
designation.  That designation will only
be permitted if such Restricted Payment, Permitted Investments or Permitted
Business Investments would be permitted under this Indenture at that time and
such Restricted Subsidiary otherwise complies with the definition of an
Unrestricted Subsidiary.  All
Subsidiaries of an Unrestricted Subsidiary shall also be Unrestricted
Subsidiaries.  Upon the designation of a
Restricted Subsidiary that is a Subsidiary Guarantor as an Unrestricted
Subsidiary, the Guarantee of such entity shall be released and the Trustee
shall be authorized to take such actions as may be appropriate to reflect such
release.

 

(b)           The Board of Directors of the General
Partner may at any time designate any Unrestricted Subsidiary to be a
Restricted Subsidiary; provided that such designation shall be deemed to be an
incurrence of Indebtedness by a Restricted Subsidiary of the Partnership of any
outstanding Indebtedness of such Unrestricted Subsidiary and such designation
shall only be permitted if (1) such Indebtedness is permitted under Section 4.09,
calculated on a pro forma basis as if such designation had occurred at the
beginning of the four-quarter reference period; and (2) no Default or
Event of Default would be in existence following such designation.

 

Section 4.15.          Business Activities.

 

The Partnership shall not, and
shall not permit any of its Restricted Subsidiaries to, engage in any business
other than Permitted Businesses, except to such extent as would not be material
to the Partnership and its Restricted Subsidiaries, taken as a whole.

 

MarkWest Finance shall not incur
Indebtedness unless (a) the Partnership is a co-obligor or guarantor of
such Indebtedness or (b) the net proceeds of such Indebtedness are loaned
to the Partnership, used to acquire outstanding debt securities issued by the
Partnership or used to repay Indebtedness of the Partnership as permitted under
Section 4.09.  MarkWest Finance
shall not

 

62

 

engage in any business not related directly or
indirectly to obtaining money or arranging financing for the Partnership or its
Restricted Subsidiaries.

 

Section 4.16.          Sale and Leaseback
Transactions.

 

The Partnership
shall not, and shall not permit any of its Restricted Subsidiaries to, enter
into any sale and leaseback transaction; provided that the Partnership or any
Restricted Subsidiary may enter into a sale and leaseback transaction if:

 

(a)           the Partnership or that Restricted
Subsidiary, as applicable, could have (i) incurred Indebtedness in an
amount equal to the Attributable Debt relating to such sale and leaseback
transaction under Section 4.09(a), and (ii) incurred a Lien to secure
such Indebtedness pursuant to Section 4.10;

 

(b)           the gross cash proceeds of that sale and
leaseback transaction are at least equal to the fair market value, as
determined in good faith by the Board of Directors of the General Partner, of
the property that is the subject of such sale and leaseback transaction; and

 

(c)           the transfer of assets in that sale and leaseback
transaction is permitted by, and the Partnership applies the proceeds of such
transaction in compliance with, the provisions set forth under Sections 3.09
and 4.07.

 

Section 4.17.          Payments for Consent.

 

The Partnership shall not, and
shall not permit any of its Subsidiaries to, directly or indirectly, pay or
cause to be paid any consideration to or for the benefit of any Holder of Notes
for or as an inducement to any consent, waiver or amendment of any of the terms
or provisions of this Indenture or the Notes unless such consideration is
offered to be paid and is paid to all Holders of the Notes that consent, waive
or agree to amend in the time frame set forth in the solicitation documents
relating to such consent, waiver or agreement.

 

Section 4.18.          Reports.

 

(a)           Whether or not required by the SEC, so long
as any Notes are outstanding, the Partnership will file with the SEC (unless
the SEC will not accept such a filing) within the time periods specified in the
SEC’s rules and regulations, and upon request, the Partnership will
furnish (without exhibits) to the Trustee for delivery to the Holders of Notes:

 

(i)            all quarterly and
annual financial information that would be required to be contained in a filing
with the SEC on Forms 10-Q and 10-K if the Partnership were required to file
such forms, including a “Management’s Discussion and Analysis of Financial
Condition and Results of Operations” and, with respect to the annual
information only, a report on the annual financial statements by the Partnership’s
certified independent accountants; and

 

(ii)           all current reports
that would be required to be filed with the SEC on Form 8-K if the
Partnership were required to file such reports.

 

63

 

(b)           If as of the end of any such quarterly or
annual period referred to in Section 4.18(a), the Partnership has
designated any of its Subsidiaries as Unrestricted Subsidiaries, then the
Partnership shall deliver (promptly after such SEC filing referred to in Section 4.18(a))
to the Trustee for delivery to the Holders of the Notes quarterly and annual
financial information required by Section 4.18(a) as revised to
include a reasonably detailed presentation, either on the face of the financial
statements or in the footnotes thereto, and in “Management’s Discussion and
Analysis of Financial Condition and Results of Operations,” of the financial
condition and results of operations of the Partnership and its Restricted
Subsidiaries separate from the financial condition and results of operations of
the Unrestricted Subsidiaries of the Partnership.

 

(c)           In addition, whether or not required by the
SEC, the Partnership will make such information available to securities
analysts, investors and prospective investors upon request.  In addition, upon request the Partnership
shall furnish the Trustee such other non-confidential information, documents
and other reports which the Partnership is required to file with the SEC
pursuant to Section 13 or Section 15(d) of the Exchange Act.

 

(d)           For so long as any Series A Notes
remain outstanding (unless the Partnership is subject to the reporting
requirements of the Exchange Act), the Partnership and the Subsidiary
Guarantors shall furnish to the Holders, upon their request, the information
required to be delivered pursuant to Rule 144A(d)(4) under the
Securities Act to the extent such information is not provided pursuant to
Sections 4.18(a) and 4.18(b).

 

(e)           Delivery of reports, information and
documents to the Trustee pursuant to this Section 4.18 is for
informational purposes only and the Trustee’s receipt of such shall not
constitute constructive notice of any information contained therein or
determinable from information contained therein, including the Partnership’s
compliance with any of its covenants hereunder (as to which the Trustee is
entitled to rely exclusively on Officers’ Certificates).

 

Section 4.19.          Termination of
Covenants.

 

If at any time the Notes have an
Investment Grade Rating from both Rating Agencies and no Default has occurred
and is continuing, the Partnership and its Restricted Subsidiaries shall no
longer be subject to the provisions of Sections 3.09, 4.07, 4.08, 4.09, 4.11,
4.12, 4.15, clauses (a)(i) and (c) of Section 4.16, and clause
(a)(iv) of Section 5.01 of this Indenture.  However, the Partnership and its Restricted
Subsidiaries will remain subject to all of the other provisions of this
Indenture.

 

ARTICLE 5

SUCCESSORS

 

Section 5.01.          Merger, Consolidation,
or Sale of Assets.

 

(a)           Neither of the Issuers may, directly or
indirectly: (x) consolidate or merge with or into another Person (whether
or not such Issuer is the survivor); or (y) sell, assign, transfer, lease,
convey or otherwise dispose of all or substantially all of its properties or
assets, in one or more related transactions, to another Person; unless:

 

64

 

(i)            either: (A) such
Issuer is the surviving entity of such transaction; or (B) the Person
formed by or surviving any such consolidation or merger (if other than such
Issuer) or to which such sale, assignment, transfer, lease, conveyance or other
disposition shall have been made is an entity organized or existing under the
laws of the United States, any state thereof or the District of Columbia,
provided that MarkWest Finance may not consolidate or merge with or into any
entity other than a corporation satisfying such requirement for so long as the
Partnership remains a partnership;

 

(ii)           the Person formed by or
surviving any such consolidation or merger (if other than such Issuer) or the
Person to which such sale, assignment, transfer, lease, conveyance or other
disposition shall have been made expressly assumes all the obligations of such
Issuer under the Notes and this Indenture pursuant to agreements reasonably
satisfactory to the Trustee;

 

(iii)          immediately after such
transaction no Default or Event of Default exists;

 

(iv)          in the case of a
transaction involving the Partnership and not MarkWest Finance, either:

 

(A)          the Partnership or the Person
formed by or surviving any such consolidation or merger (if other than the
Partnership) shall, on the date of such transaction after giving pro forma
effect thereto and any related financing transactions as if the same had
occurred at the beginning of the applicable four-quarter period, be permitted
to incur at least $1.00 of additional Indebtedness pursuant to the Fixed Charge
Coverage Ratio test set forth in Section 4.09(a); or

 

(B)           immediately after
giving effect to such transaction on a pro forma basis and any related
financing transactions as if the same had occurred at the beginning of the
applicable four-quarter period, the Fixed Charge Coverage Ratio of the
Partnership or the Person formed by or surviving any such consolidation or
merger (if other than the Partnership) or to which such sale, assignment,
transfer, lease, conveyance or other disposition has been made, will be equal
to or greater than the Fixed Charge Coverage Ratio of the Partnership
immediately before such transactions; and

 

(v)           such Issuer has
delivered to the Trustee an Officers’ Certificate and an Opinion of Counsel,
each stating that such consolidation, merger or disposition and, if a
supplemental indenture is required, such supplemental indenture comply with
this Indenture and all conditions precedent therein relating to such
transaction have been satisfied.

 

(b)           Notwithstanding Section 5.01(a),
the Partnership is permitted to reorganize as any other form of entity in
accordance with the procedures established in this Indenture; provided that:

 

(i)            the reorganization
involves the conversion (by merger, sale, contribution or exchange of assets or
otherwise) of the Partnership into a form of entity other than a limited
partnership formed under Delaware law;

 

65

 

(ii)           the entity so formed by
or resulting from such reorganization is an entity organized or existing under
the laws of the United States, any state thereof or the District of Columbia;

 

(iii)          the entity so formed by
or resulting from such reorganization assumes all of the obligations of the
Partnership under the Notes and this Indenture pursuant to agreements
reasonably satisfactory to the Trustee;

 

(iv)          immediately after such
reorganization no Default or Event of Default exists; and

 

(v)           such reorganization is
not adverse to the Holders of the Notes (for purposes of this clause (v) it
is stipulated that such reorganization shall not be considered adverse to the
Holders of the Notes solely because the successor or survivor of such
reorganization (A) is subject to federal or state income taxation as an
entity or (B) is considered to be an “includible corporation” of an
affiliated group of corporations within the meaning of Section 1504(b)(i) of
the Code or any similar state or local law).

 

(c)           No Subsidiary Guarantor may consolidate with
or merge with or into (whether or not such Subsidiary Guarantor is the
surviving Person) another Person, except the Partnership or another Subsidiary
Guarantor, unless (i) immediately after giving effect to such transaction,
no Default or Event of Default exists, and (ii) the Person formed by or
surviving any such consolidation or merger assumes all the obligations of such
Subsidiary Guarantor pursuant to the Subsidiary Guarantor’s Guarantee of the
Notes and this Indenture pursuant to a supplemental indenture substantially in
the form of Annex A hereto, except that no such assumption or supplemental
indenture shall be required in those circumstances described in clauses (i) and
(ii) of Section 10.05 hereof. 
In case of any such consolidation or merger and upon the assumption by
the successor Person by supplemental indenture, executed and delivered to the
Trustee substantially in the form of Annex A hereto, of the Guarantees
contained herein and the due and punctual performance of all of the covenants
of this Indenture to be performed by the Subsidiary Guarantor, such successor
shall succeed to and be substituted for the Subsidiary Guarantor with the same
effect as if it had been named herein as a Subsidiary Guarantor.  Such successor thereupon may cause to be
signed any or all of the notations of the Guarantees to be endorsed upon all of
the Notes issuable hereunder which theretofore shall not have been signed by
the Issuers and delivered to the Trustee. 
All the Guarantees so issued shall in all respects have the same legal
rank and benefit under this Indenture as the Guarantees theretofore and
thereafter issued in accordance with the terms of this Indenture as though all
of such Guarantees had been issued at the date of the execution hereof.

 

Section 5.02.          Successor Entity
Substituted.

 

(a)           Upon any consolidation or merger, or any
sale, assignment, transfer, lease, conveyance or other disposition of all or
substantially all of the properties or assets of an Issuer in accordance with Section 5.01
hereof, the surviving entity formed by such consolidation or into or with which
such Issuer is merged or to which such sale, assignment, transfer, lease,
conveyance or other disposition is made shall succeed to, and be substituted
for (so that from and after the date of such consolidation, merger, sale,
assignment, transfer, lease, conveyance or

 

66

 

other disposition, the provisions of this
Indenture referring to the “Partnership” or “MarkWest Finance,” as the case may
be, shall refer instead to the surviving entity and not to the Partnership or
MarkWest Finance, as the case may be), and may exercise every right and power
of the Partnership or MarkWest Finance, as the case may be, under this
Indenture with the same effect as if such successor Person had been named as an
Issuer herein; and thereafter, if an Issuer is dissolved following a
disposition of all or substantially all of its properties or assets in accordance
with this Indenture, it shall be discharged and released from all obligations
and covenants under this Indenture and the Notes; provided, however, that the
predecessor shall not be relieved from the obligation to pay the principal of
and interest on the Notes in the case of a lease of all or substantially all of
its properties or assets.

 

(b)           If the surviving entity shall have succeeded
to and been substituted for an Issuer, such surviving entity may cause to be
signed, and may issue either in its own name or in the name of the applicable
Issuer prior to such succession any or all of the Notes issuable hereunder
which theretofore shall not have been signed by such Issuer and delivered to
the Trustee; and, upon the order of such surviving entity, instead of such
Issuer, and subject to all the terms, conditions and limitations in this
Indenture prescribed, the Trustee shall authenticate and shall deliver any
Notes which previously shall have been signed and delivered by the Officers of
such Issuer to the Trustee for authentication, and any Notes which such
surviving entity thereafter shall cause to be signed and delivered to the
Trustee for that purpose (in each instance with notations of Guarantees thereon
by the Subsidiary Guarantors).  All of
the Notes so issued and so endorsed shall in all respects have the same legal
rank and benefit under this Indenture as the Notes theretofore or thereafter
issued and endorsed in accordance with the terms of this Indenture and the
Guarantees as though all such Notes had been issued and endorsed at the date of
the execution hereof.

 

(c)           In case of any such consolidation, merger,
sale, assignment, transfer, lease, conveyance or other disposition, such
changes in phraseology and form (but not in substance) may be made in the Notes
thereafter to be issued or the Guarantees to be endorsed thereon as may be
appropriate.

 

(d)           For all purposes of this Indenture and the
Notes, Subsidiaries of any surviving entity (other than an Issuer) will, upon
such transaction or series of transactions, become Restricted Subsidiaries or
Unrestricted Subsidiaries as provided pursuant to this Indenture and all
Indebtedness, and all Liens on property or assets, of such surviving entity and
its Restricted Subsidiaries immediately prior to such transaction or series of
transactions shall be deemed to have been incurred upon such transaction or
series of transactions.

 

ARTICLE 6

DEFAULTS AND
REMEDIES

 

Section 6.01.          Events of Default.

 

Each of the
following is an “Event of Default”:

 

(a)           default for 30 days in the payment when due
of interest on, including Additional Interest with respect to, the Notes;

 

67

 

(b)           default in payment when due of the principal
of or premium, if any, on the Notes;

 

(c)           failure by the Partnership to comply with
the provisions described under Section 5.01 hereof;

 

(d)           failure by the Partnership to comply with
the provisions described under Section 4.18 hereof for 90 days after
notice to the Issuers by the Trustee or to the Issuers and Trustee by Holders
of at least 25% in aggregate principal amount of the Notes then outstanding;

 

(e)           subject to Section 4.19, failure by the
Partnership to comply with the provisions described under Section 3.09,
4.06, 4.07, 4.08, 4.09, 4.10, 4.11. 4.12, 4.13, 4.14, 4.15, 4.16 or 4.17 hereof
for 30 days after notice to the Issuers by the Trustee or to the Issuers and
Trustee by Holders of at least 25% in aggregate principal amount of the Notes
then outstanding (provided that no such notice need be given, and an Event of
Default shall occur, 30 days after a failure to comply with the covenants in Section 4.08
or 4.09 hereof, unless theretofore cured), in each case other than a failure to
purchase Notes which will constitute an Event of Default under clause (b) of
this Section 6.01;

 

(f)            failure by the Partnership to comply with
any of its other agreements in this Indenture for 60 days after notice to the
Issuers by the Trustee or to the Issuers and Trustee by Holders of at least 25%
in aggregate principal amount of the Notes then outstanding;

 

(g)           default under any mortgage, indenture or
instrument under which there may be issued or by which there may be secured or
evidenced any Indebtedness for money borrowed by either Issuer or any of the
Restricted Subsidiaries of the Partnership (or the payment of which is
guaranteed by either Issuer or any of such Restricted Subsidiaries), whether
such Indebtedness or guarantee now exists or is created after the date of this
Indenture, if that default:

 

(i)            is caused by a failure
to pay principal of or premium, if any, or interest on such Indebtedness prior
to the expiration of the grace period provided in such Indebtedness (a “Payment
Default”), or

 

(ii)           results in the
acceleration of such Indebtedness prior to its express maturity,

 

and, in each case, the principal amount of any
such Indebtedness, together with the principal amount of any other such
Indebtedness under which there has been a Payment Default or the maturity of
which has been so accelerated, aggregates $20.0 million or more; provided that
if any such default is cured or waived or any such acceleration rescinded, or
such Indebtedness is repaid, within a period of 30 days from the continuation
of such default beyond the applicable grace period or the occurrence of such
acceleration, as the case may be, such Event of Default and any consequential
acceleration of the Notes shall be automatically rescinded, so long as such
rescission does not conflict with any judgment or decree;

 

(h)           failure by an Issuer or any Restricted
Subsidiary of the Partnership to pay final judgments aggregating in excess of
$20.0 million, which judgments are not paid, discharged or stayed for a period
of 60 days;

 

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(i)            except as permitted by this Indenture, any
Guarantee shall be held in any judicial proceeding to be unenforceable or
invalid or shall cease for any reason to be in full force and effect or any
Subsidiary Guarantor, or any Person acting on behalf of any Subsidiary Guarantor,
shall deny or disaffirm its obligations under its Guarantee;

 

(j)            either Issuer or any Restricted Subsidiary
of the Partnership that is a Significant Subsidiary or any group of Restricted
Subsidiaries of the Partnership that, taken as a whole, would constitute a
Significant Subsidiary, pursuant to or within the meaning of Bankruptcy Law:

 

(i)            commences a voluntary
case,

 

(ii)           consents to the entry
of an order for relief against it in an involuntary case,

 

(iii)          consents to the
appointment of a custodian of it or for all or substantially all of its
property,

 

(iv)          makes a general
assignment for the benefit of its creditors, or

 

(v)           generally is not paying
its debts as they become due; and

 

(k)           a court of competent
jurisdiction enters an order or decree under any Bankruptcy Law that:

 

(i)            is for relief against
an Issuer or any Restricted Subsidiary of the Partnership that is a Significant
Subsidiary or any group of Restricted Subsidiaries of the Partnership that,
taken as a whole, would constitute a Significant Subsidiary in an involuntary
case;

 

(ii)           appoints a custodian of
an Issuer or any Restricted Subsidiary of the Partnership that is a Significant
Subsidiary or any group of Restricted Subsidiaries of the Partnership that,
taken as a whole, would constitute a Significant Subsidiary or for all or
substantially all of the property of an Issuer or any Restricted Subsidiary of
the Partnership that is a Significant Subsidiary or any group of Restricted
Subsidiaries of the Partnership that, taken as a whole, would constitute a
Significant Subsidiary; or

 

(iii)          orders the liquidation
of an Issuer or any Restricted Subsidiary of the Partnership that is a
Significant Subsidiary or any group of Restricted Subsidiaries of the
Partnership that, taken as a whole, would constitute a Significant Subsidiary;

 

and the order or decree remains unstayed and
in effect for 60 consecutive days.

 

Section 6.02.          Acceleration.

 

If any Event of Default (other
than an Event of Default specified in clause (j) or (k) of Section 6.01
hereof) occurs and is continuing, the Trustee may, and upon written request of
the Holders of at least 25% in aggregate principal amount of the then
outstanding Notes shall, declare all the Notes to be due and payable
immediately.  Upon any such declaration,
the Notes shall become due and payable immediately.  Notwithstanding the foregoing, if an Event of

 

69

 

Default specified in clause (j) or (k) of
Section 6.01 hereof occurs with respect to an Issuer, all outstanding
Notes shall be due and payable immediately without further action or
notice.  The Holders of a majority in
aggregate principal amount of the then outstanding Notes by written notice to
the Trustee may on behalf of the Holders of all of the Notes rescind an
acceleration and its consequences if the rescission would not conflict with any
judgment or decree and if all existing Events of Default (except nonpayment of
principal, interest or premium that has become due solely because of the
acceleration) have been cured or waived.

 

Section 6.03.          Other Remedies.

 

If an Event of Default occurs
and is continuing, the Trustee may pursue any available remedy to collect the
payment of principal, premium, if any, and interest (including Additional
Interest, if any) on the Notes or to enforce the performance of any provision
of the Notes or this Indenture.

 

The Trustee may maintain a
proceeding even if it does not possess any of the Notes or does not produce any
of them in the proceeding.  A delay or
omission by the Trustee or any Holder of a Note in exercising any right or
remedy accruing upon an Event of Default shall not impair the right or remedy
or constitute a waiver of or acquiescence in the Event of Default.  All remedies are cumulative to the extent
permitted by law.

 

Section 6.04.          Waiver of Past Defaults.

 

Holders of not less than a
majority in aggregate principal amount of the then outstanding Notes by notice
to the Trustee may on behalf of the Holders of all of the Notes waive an
existing Default or Event of Default and its consequences hereunder, except a
continuing Default or Event of Default in the payment of the principal of,
premium and/or interest (including Additional Interest, if any) on, the Notes
(including in connection with an offer to purchase) (provided, however, that
the Holders of a majority in aggregate principal amount of the then outstanding
Notes may rescind an acceleration and its consequences, including any related
payment default that resulted from such acceleration).  Upon any such waiver, such Default shall
cease to exist, and any Event of Default arising therefrom shall be deemed to
have been cured for every purpose of this Indenture; but no such waiver shall
extend to any subsequent or other Default or impair any right consequent thereon.

 

Section 6.05.          Control by Majority.

 

Holders of a majority in
aggregate principal amount of the then outstanding Notes may direct the time,
method and place of conducting any proceeding for exercising any remedy
available to the Trustee or exercising any trust or power conferred on it.  However, the Trustee may refuse to follow any
direction that conflicts with law or this Indenture or that the Trustee
determines may be unduly prejudicial to the rights of other Holders of Notes or
that may involve the Trustee in personal liability.

 

70

 

Section 6.06.          Limitation on Suits.

 

A Holder of a
Note may pursue a remedy with respect to this Indenture or the Notes only if:

 

(a)           the Holder of a Note gives to the Trustee
written notice of a continuing Event of Default;

 

(b)           the Holders of at least 25% in principal
amount of the then outstanding Notes make a written request to the Trustee to
pursue the remedy;

 

(c)           such Holder of a Note or Holders of Notes
offer and, if requested, provide to the Trustee indemnity or security
satisfactory to the Trustee against any loss, liability or expense;

 

(d)           the Trustee does not comply with the request
within 60 days after receipt of the request and the offer and, if requested,
the provision of indemnity; and

 

(e)           during such 60-day period the Holders of a
majority in principal amount of the then outstanding Notes do not give the
Trustee a direction inconsistent with the request.

 

A Holder of a Note may not use
this Indenture to prejudice the rights of another Holder of a Note or to obtain
a preference or priority over another Holder of a Note.

 

Section 6.07.          Rights of Holders of
Notes to Receive Payment.

 

Notwithstanding any other
provision of this Indenture, the right of any Holder of a Note to receive
payment of principal, premium and interest (including Additional Interest, if
any) on the Note, on or after the respective due dates expressed in the Note
(including in connection with an offer to purchase), or to bring suit for the
enforcement of any such payment on or after such respective dates, shall not be
impaired or affected without the consent of such Holder.

 

Section 6.08.          Collection Suit by
Trustee.

 

If an Event of Default specified
in Section 6.01(a) or (b) occurs and is continuing, the Trustee
is authorized to recover a judgment in its own name and as trustee of an
express trust against the Issuers for the whole amount of principal of, premium
and interest (including Additional Interest, if any) remaining unpaid on the
Notes and interest on overdue principal and, to the extent lawful, interest
(including Additional Interest, if any) and such further amount as shall be
sufficient to cover the costs and expenses of collection, including the
reasonable compensation, expenses, disbursements and advances of the Trustee,
its agents and counsel.

 

Section 6.09.          Trustee May File
Proofs of Claim.

 

The Trustee is authorized to
file such proofs of claim and other papers or documents as may be necessary or
advisable in order to have the claims of the Trustee (including any claim for
the reasonable compensation, expenses, disbursements and advances of the
Trustee, its agents and counsel) and the Holders of the Notes allowed in any
judicial proceedings relative to an Issuer or any of the Subsidiary Guarantors
(or any other obligor upon the Notes), its creditors or

 

71

 

its property and shall be entitled and
empowered to collect, receive and distribute any money or other property
payable or deliverable on any such claims and any custodian in any such
judicial proceeding is hereby authorized by each Holder to make such payments
to the Trustee, and in the event that the Trustee shall consent to the making
of such payments directly to the Holders, to pay to the Trustee any amount due
to it for the reasonable compensation, expenses, disbursements and advances of
the Trustee, its agents and counsel, and any other amounts due the Trustee
under Section 7.07 hereof.  To the
extent that the payment of any such compensation, expenses, disbursements and
advances of the Trustee, its agents and counsel, and any other amounts due the
Trustee under Section 7.07 hereof out of the estate in any such
proceeding, shall be denied for any reason, payment of the same shall be
secured by a Lien on, and shall be paid out of, any and all distributions,
dividends, money, securities and other properties that the Holders may be
entitled to receive in such proceeding whether in liquidation or under any plan
of reorganization or arrangement or otherwise. 
Nothing herein contained shall be deemed to authorize the Trustee to
authorize or consent to or accept or adopt on behalf of any Holder any plan of
reorganization, arrangement, adjustment or composition affecting the Notes or
the rights of any Holder, or to authorize the Trustee to vote in respect of the
claim of any Holder in any such proceeding.

 

Section 6.10.          Priorities.

 

If the Trustee collects any
money pursuant to this Article, it shall pay out the money in the following
order:

 

First: to the Trustee, its
agents and attorneys for amounts due under Section 7.07 hereof, including
payment of all compensation, expense and liabilities incurred, and all advances
made, by the Trustee and the costs and expenses of collection;

 

Second: to Holders of Notes for
amounts due and unpaid on the Notes for principal, premium and interest
(including Additional Interest, if any), ratably, without preference or
priority of any kind, according to the amounts due and payable on the Notes for
principal, premium and interest (including Additional Interest, if any),
respectively; and

 

Third: to the Issuers or the
Subsidiary Guarantors or to such other party as a court of competent
jurisdiction shall direct.

 

The Trustee may fix a record
date and payment date for any payment to Holders of Notes pursuant to this Section 6.10.

 

Section 6.11.          Undertaking for Costs.

 

In any suit for the enforcement
of any right or remedy under this Indenture or in any suit against the Trustee
for any action taken or omitted by it as a Trustee, a court in its discretion
may require the filing by any party litigant in the suit of an undertaking to
pay the costs of the suit, and the court in its discretion may assess
reasonable costs, including reasonable attorneys’ fees and expenses against any
party litigant in the suit, having due regard to the merits and good faith of
the claims or defenses made by the party litigant.  This Section 6.11 does not apply to a
suit by the Trustee, a suit by a Holder of a Note pursuant to Section 6.07
hereof, or a suit by Holders of more than 10% in principal amount of the then
outstanding Notes.

 

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ARTICLE 7

TRUSTEE

 

Section 7.01.          Duties of Trustee.

 

(a)           If an Event of Default has occurred and is
continuing, the Trustee shall exercise such of the rights and powers vested in
it by this Indenture, and use the same degree of care and skill in its
exercise, as a prudent man would exercise or use under the circumstances in the
conduct of his own affairs.

 

(b)           Except during the
continuance of an Event of Default:

 

(i)            the duties of the
Trustee shall be determined solely by the express provisions of this Indenture
and the Trustee need perform only those duties that are specifically set forth
in this Indenture and no others, and no implied covenants or obligations shall
be read into this Indenture against the Trustee; and

 

(ii)           in the absence of bad
faith on its part, the Trustee may conclusively rely, as to the truth of the
statements and the correctness of the opinions expressed therein, upon
certificates or opinions furnished to the Trustee and conforming to the
requirements of this Indenture.  However,
in the case of any such certificates or opinions which by any provision hereof
are specifically required to be furnished to the Trustee, the Trustee shall be
under a duty to examine the same to determine whether or not they conform to
the requirements of this Indenture (but need not confirm or investigate the
accuracy of mathematical calculations or other facts stated therein).

 

(c)           The Trustee may not be
relieved from liabilities for its own negligent action, its own negligent
failure to act, or its own willful misconduct, except that:

 

(i)            this paragraph does
not limit the effect of paragraph (b) of this Section;

 

(ii)           the Trustee shall not
be liable for any error of judgment made in good faith by a Responsible
Officer, unless it is proved that the Trustee was negligent in ascertaining the
pertinent facts; and

 

(iii)          the Trustee shall not be
liable with respect to any action it takes or omits to take in good faith in
accordance with a direction received by it pursuant to any provision of this
Indenture relating to the time, method and place of conducting any proceeding
or remedy available to the Trustee, or exercising any trust or power conferred
upon the Trustee under this Indenture.

 

(d)           Whether or not therein expressly so
provided, every provision of this Indenture that in any way relates to the
Trustee is subject to paragraphs (a), (b), and (c) of this Section.

 

(e)           No provision of this Indenture shall require
the Trustee to expend or risk its own funds or otherwise incur any financial
liability.  The Trustee shall be under no
obligation to exercise any of its rights and powers under this Indenture at the
request of any Holders, unless

 

73

 

such Holder shall have offered to the Trustee
security or indemnity satisfactory to it against any claim, loss, liability or
expense.

 

(f)            The Trustee shall not be liable for interest
on any money received by it except as the Trustee may agree in writing with the
Partnership or MarkWest Finance.  Money
held in trust by the Trustee need not be segregated from other funds except to
the extent required by law.

 

Section 7.02.          Rights of Trustee.

 

(a)           Subject to the provisions of Section 7.01(a) hereof,
the Trustee may conclusively rely upon any document believed by it to be
genuine and to have been signed or presented by the proper Person.  The Trustee need not investigate any fact or
matter stated in the document, but may accept the same as conclusive evidence
of the truth and accuracy of such statement or the correctness of such opinion.

 

(b)           Before the Trustee acts or refrains from
acting in the administration of this Indenture, it may require an Officers’
Certificate or an Opinion of Counsel or both. 
The Trustee shall not be liable for any action it takes or omits to take
in good faith in reliance on such Officers’ Certificate or Opinion of
Counsel.  The Trustee may consult with
counsel of its selection and the advice of such counsel or any Opinion of
Counsel shall be full and complete authorization and protection from liability
in respect of any action taken, suffered or omitted by it hereunder in good
faith and in reliance thereon.

 

(c)           The Trustee may execute any of its trusts or
powers or perform any duties under this Indenture either directly by or through
agents or attorneys, and may in all cases pay, subject to reimbursement as
provided herein, such reasonable compensation as it deems proper to all such
agents and attorneys employed or retained by it, and the Trustee shall not be
responsible for any misconduct or negligence of any agent or attorney appointed
with due care.

 

(d)           The Trustee shall not be liable for any
action it takes or omits to take in good faith that it believes to be
authorized or within the rights or powers conferred upon it by this Indenture.

 

(e)           Unless otherwise specifically provided in
this Indenture, any demand, request, direction or notice from an Issuer or any
Subsidiary Guarantor shall be sufficient if signed by an Officer of the
Partnership or the General Partner (in the case of the Partnership), by an
Officer of the General Partner (in the case of the General Partner) or by an
Officer of MarkWest Finance or any Subsidiary Guarantor (in the case of
MarkWest Finance or such Subsidiary Guarantor).

 

(f)            The Trustee shall be under no obligation to
exercise any of the rights or powers vested in it by this Indenture at the
request or direction of any of the Holders unless such Holders shall have
offered to the Trustee reasonable security or indemnity against the claims,
costs, expenses and liabilities that might be incurred by it in compliance with
such request or direction.

 

(g)           The Trustee is not required to make any
inquiry or investigation into facts or matters stated in any document but the
Trustee, in its discretion, may make such further inquiry or investigation into
such facts or matters as it may see fit and, if the Trustee determines to make

 

74

 

such further inquiry or investigation, it
shall be entitled to examine the books, records and premises of the Issuers.

 

(h)           The Trustee is not required to take notice
or shall not be deemed to have notice of any Default or Event of Default
hereunder except Defaults or Events of Default under Sections 6.01(a) and
6.01(b) hereof, unless a Responsible Officer of the Trustee has actual
knowledge thereof or has received notice in writing of such Default or Event of
Default from the Issuers or the Holders of at least 25% in aggregate principal
amount of the Notes then outstanding, and in the absence of any such notice,
the Trustee may conclusively assume that no such Default or Event of Default
exists.

 

(i)            The Trustee is not required to give any
bond or surety with respect to the performance of its duties or the exercise of
its powers under this Indenture.

 

(j)            Under no circumstances shall the Trustee be
liable in its individual capacity for the obligations evidenced by the Notes.

 

(k)           In the event the Trustee receives
inconsistent or conflicting requests and indemnity from two or more groups of
Holders of Notes, each representing less than the aggregate principal amount of
Notes outstanding required to take any action hereunder, the Trustee, in its
sole discretion may determine what action, if any, shall be taken.

 

(l)            The Trustee’s immunities and protections
from liability and its right to indemnification in connection with the
performance of its duties under this Indenture shall extend to the Trustee’s
officers, directors, agents, attorneys and employees.  Such immunities and protections and right to
indemnification, together with the Trustee’s right to compensation, shall
survive the Trustee’s resignation of removal, the discharge of this Indenture
and final payments of the Notes.

 

(m)          The permissive right of the Trustee to take
actions permitted by this Indenture shall not be construed as an obligation or
duty to do so.

 

(n)           Except for information provided by the
Trustee concerning the Trustee, the Trustee shall have no responsibility for
any information and any offering memorandum, disclosure material or prospectus
distributed with respect to the Notes.

 

(o)           The Trustee shall not be liable for any
action taken or omitted by it in good faith at the direction of the Holders of
not less than a majority in aggregate principal amount of the Notes as to the
time, method, and place of conducting any proceedings for any remedy available
to the Trustee or the exercising of any power conferred by this Indenture.

 

(p)           Subject to Section 7.01(d), whether or
not therein expressly so provided, every provision of this Indenture relating
to the conduct of, or affecting the liability of, or affording protection to
the Trustee shall be subject to the provisions of this Section 7.02.

 

(q)           Any action taken, or omitted to be taken, by
the Trustee in good faith, pursuant to this Indenture upon the request or
authority or consent of any Person who, at the time of making such request or
giving such authority or consent, is the Holder of any Note shall be conclusive

 

75

 

and binding upon all future Holders of that
Note and upon securities executed and delivered in exchange therefore or in
place thereof.

 

Section 7.03.          Individual Rights of
Trustee.

 

The Trustee in its commercial
banking or any other capacity may become the owner or pledgee of Notes and may
otherwise deal with the Issuers, any Subsidiary Guarantors or any Affiliate of
the Partnership with the same rights it would have if it were not Trustee.  Any Affiliate of the Trustee or Agent may do
the same with like rights and duties. 
However, in the event that the Trustee acquires any conflicting interest
(as defined in the TIA) after a Default has occurred and is continuing it must
eliminate such conflict within 90 days, apply to the SEC for permission to
continue as trustee or resign.  The
Trustee is also subject to Sections 7.10 and 7.11 hereof.

 

Section 7.04.          Trustee’s Disclaimer.

 

The Trustee shall not be
responsible for and makes no representation as to the validity or adequacy of
this Indenture, the Notes or the Guarantees, it shall not be accountable for
the Issuers’ use of the proceeds from the Notes or any money paid to an Issuer
or upon an Issuer’s direction under any provision of this Indenture, it shall
not be responsible for the use or application of any money received by any
Paying Agent other than the Trustee, and it shall not be responsible for any
statement or recital herein or any statement in the Notes or any other document
in connection with the sale of the Notes or pursuant to this Indenture other
than its certificate of authentication.

 

Section 7.05.          Notice of Defaults.

 

If a Default or Event of Default
known to the Trustee occurs, the Trustee shall mail to Holders of Notes a
notice of the Default or Event of Default within 90 days after it occurs.  Except in the case of a Default or Event of
Default in payment of principal of, premium, if any, or interest (including
Additional Interest, if any) on any Note, the Trustee may withhold the notice
if and so long as a committee of its Responsible Officers in good faith
determines that withholding the notice is in the interests of the Holders of
the Notes.

 

Section 7.06.          Reports by Trustee to
Holders of the Notes.

 

Within 60 days after each May 15
beginning with the May 15 following the date of this Indenture, and for so
long as Notes remain outstanding, the Trustee shall mail to the Holders of the
Notes a brief report dated as of such reporting date that complies with TIA Section 313(a) (but
if no event described in TIA Section 313(a) has occurred within the
twelve months preceding the reporting date, no report need be
transmitted).  The Trustee also shall
comply with TIA Section 313(b)(2). 
The Trustee shall also transmit by mail all reports as required by TIA Section 313(c).

 

A copy of each report at the
time of its mailing to the Holders of Notes shall be mailed to the Partnership
and filed with the SEC and each stock exchange on which the Notes are listed in
accordance with TIA Section 313(d). 
The Issuers shall promptly notify the Trustee when the Notes are listed
on any stock exchange.

 

76

 

Section 7.07.          Compensation and
Indemnity.

 

The Issuers and the Subsidiary
Guarantors shall pay to the Trustee from time to time such compensation as
shall be agreed upon in writing between the Issuers and the Trustee for its
acceptance of this Indenture and services hereunder.  The Trustee’s compensation shall not be
limited by any law on compensation of a trustee of an express trust.  The Issuers and the Subsidiary Guarantors
shall reimburse the Trustee promptly upon request for all reasonable
disbursements, advances and expenses incurred or made by it in addition to the
compensation for its services.  Such
expenses shall include the reasonable compensation, disbursements and expenses
of the Trustee’s agents and counsel.

 

The Issuers and the Subsidiary
Guarantors shall indemnify each of the Trustee or any successor Trustee against
any and all losses, damages, claims, liabilities or expenses (including
reasonable attorneys’ fees and expenses) incurred by it arising out of or in
connection with the acceptance or administration of its duties under this Indenture,
including the costs and expenses of enforcing this Indenture against either of
the Issuers or any Subsidiary Guarantor (including this Section 7.07) and
defending itself against any claim (whether asserted by an Issuer, any
Subsidiary Guarantor, or any Holder or any other Person) or liability in
connection with the exercise or performance of any of its powers or duties
hereunder, except to the extent any such loss, liability or expense may be
attributable to its negligence or bad faith. 
The Trustee shall notify the Issuers promptly of any claim for which it
may seek indemnity.  Failure by the
Trustee to so notify the Issuers shall not relieve the Issuers and the
Subsidiary Guarantors of their obligations hereunder.  The Issuers and the Subsidiary Guarantors
shall defend the claim and the Trustee shall cooperate in the defense.  The Trustee may have separate counsel and the
Issuers and the Subsidiary Guarantors shall pay the reasonable fees and
expenses of such separate counsel; provided that the Issuers and the Subsidiary
Guarantors will not be required to pay such fees and expenses if they assume
the Trustee’s defense with counsel acceptable to and approved by the Trustee
(such approval not to be unreasonably withheld) and there is no conflict of
interest between the Issuers and the Trustee in connection with such
defense.  The Issuers and the Subsidiary
Guarantors need not pay for any settlement made without their consent, which
consent shall not be unreasonably withheld. 
Neither the Issuers nor the Subsidiary Guarantors need reimburse the
Trustee for any expense or indemnity against any liability or loss of the
Trustee to the extent such expense, liability or loss is attributable to the
negligence or bad faith of the Trustee.

 

The obligations of the Issuers
and the Subsidiary Guarantors under this Section 7.07 shall survive the
satisfaction and discharge of this Indenture.

 

To secure the Issuers’ and the
Subsidiary Guarantors’ payment obligations in this Section, the Trustee shall
have a Lien (which it may exercise through right of set-off) prior to the Notes
on all money or property held or collected by the Trustee, except that held in
trust to pay principal, premium, if any, and interest (including Additional
Interest, if any) on particular Notes.  Such
Lien shall survive the satisfaction and discharge of this Indenture.  When the Trustee incurs expenses or renders
services after an Event of Default specified in Section 6.01(j) or (k) hereof
occurs, the expenses and the compensation for the services (including the fees
and expenses of its agents and counsel) are intended to constitute expenses of
administration under any Bankruptcy Law.

 

77

 

The Trustee shall comply with
the provisions of TIA Section 313(b)(2) to the extent applicable.

 

Section 7.08.          Replacement of Trustee.

 

A resignation or removal of the
Trustee and appointment of a successor Trustee shall become effective only upon
the successor Trustee’s acceptance of appointment as provided in this Section.  The Trustee may resign in writing at any time
and be discharged from the trust hereby created by so notifying the
Issuers.  The Holders of Notes of a
majority in principal amount of the then outstanding Notes may remove the
Trustee by so notifying the Trustee and the Issuers in writing.  The Issuers may remove the Trustee if:

 

(a)           the Trustee fails to comply with Section 7.10
hereof;

 

(b)           the Trustee is adjudged a bankrupt or an
insolvent or an order for relief is entered with respect to the Trustee under
any Bankruptcy Law;

 

(c)           a custodian or public officer takes charge
of the Trustee or its property; or

 

(d)           the Trustee becomes incapable of acting.

 

If the Trustee resigns or is
removed or if a vacancy exists in the office of Trustee for any reason, the
Issuers shall promptly appoint a successor Trustee.  Within one year after the successor Trustee
takes office, the Holders of a majority in aggregate principal amount of the
then outstanding Notes may appoint a successor Trustee to replace the successor
Trustee appointed by the Issuers.

 

If a successor Trustee does not
take office within 60 days after the retiring Trustee resigns or is removed,
the retiring Trustee, the Issuers, any Subsidiary Guarantor or the Holders of
Notes of at least 10% in aggregate principal amount of the then outstanding
Notes may petition any court of competent jurisdiction for the appointment of a
successor Trustee.

 

If the Trustee, after written
request by any Holder of a Note who has been a Holder of a Note for at least
six months, fails to comply with Section 7.10, such Holder of a Note may
petition any court of competent jurisdiction for the removal of the Trustee and
the appointment of a successor Trustee.

 

A successor Trustee shall
deliver a written acceptance of its appointment to the retiring Trustee and to
the Issuers.  Thereupon, the resignation
or removal of the retiring Trustee shall become effective, and the successor
Trustee shall have all the rights, powers and duties of the Trustee under this
Indenture.  The successor Trustee shall
mail a notice of its succession to Holders of the Notes.  The retiring Trustee shall promptly transfer
all property held by it as Trustee to the successor Trustee, provided all sums
owing to the Trustee hereunder have been paid and subject to the Lien provided
for in Section 7.07 hereof. 
Notwithstanding replacement of the Trustee pursuant to this Section 7.08,
the Issuers’ and the Subsidiary Guarantors’ obligations under Section 7.07
hereof shall continue for the benefit of the retiring Trustee.

 

78

 

Section 7.09.          Successor Trustee by
Merger, Etc.

 

If the Trustee consolidates,
merges or converts into, or transfers all or substantially all of its corporate
trust business to, another corporation or association, the successor
corporation or association without any further act shall be the successor
Trustee.  As soon as practicable, the
successor Trustee shall mail a notice of its succession to the Issuers and the
Holders of the Notes.

 

Section 7.10.          Eligibility;
Disqualification.

 

There shall at all times be a
Trustee hereunder that is a corporation or association organized and doing
business under the laws of the United States of America or of any state thereof
that is authorized under such laws to exercise corporate trust powers, that is
subject to supervision or examination by federal or state authorities and that
has a combined capital and surplus of at least $50 million as set forth in its
most recent published annual report of condition.

 

This Indenture shall always have
a Trustee who satisfies the requirements of TIA Section 310(a)(1), (2) and
(5).  The Trustee is subject to TIA Section 310(b),
provided, however, that there shall be excluded from the operation of TIA Section 310(b)(l) any
indenture or indentures under which other securities or certificates of
interest or participation in other securities of the Issuers are outstanding if
the requirements of such exclusion set forth in TIA Section 310(b)(l) are
met.  For purposes of the preceding
sentence, the optional provision permitted by the second sentence of Section 310(b)(9) of
the Trust Indenture Act shall be applicable.

 

Section 7.11.          Preferential Collection
of Claims Against Issuers.

 

The Trustee is subject to TIA Section 311(a),
excluding any creditor relationship listed in TIA Section 311(b).  A Trustee who has resigned or been removed
shall be subject to TIA Section 311(a) to the extent indicated
therein.

 

ARTICLE 8

LEGAL
DEFEASANCE AND COVENANT DEFEASANCE

 

Section 8.01.          Option to Effect Legal
Defeasance or Covenant Defeasance.

 

The Issuers may, at the option
of the Board of Directors of the General Partner (in the case of the
Partnership) or of the Board of Directors of MarkWest Finance (in the case of
MarkWest Finance) evidenced by a resolution set forth in an Officers’
Certificate, at any time, elect to have either Section 8.02 or 8.03 hereof
be applied to all outstanding Notes upon compliance with the conditions set
forth below in this Article 8.

 

Section 8.02.          Legal Defeasance and
Discharge.

 

Upon the Issuers’ exercise under
Section 8.01 hereof of the option applicable to this Section 8.02,
the Issuers and the Subsidiary Guarantors shall, subject to the satisfaction of
the conditions set forth in Section 8.04 hereof, be deemed to have been
discharged from their respective Obligations and certain other obligations with
respect to all outstanding Notes and Guarantees, as applicable, on the date the
conditions set forth below are satisfied (hereinafter, “Legal Defeasance”).  For this purpose, Legal Defeasance means that
the Issuers and the

 

79

 

Subsidiary Guarantors shall be deemed to have
paid and discharged the entire Indebtedness represented by the outstanding
Notes, which shall thereafter be deemed to be “outstanding” only for the
purposes of Section 8.05 hereof and the other Sections of this Indenture
referred to in clauses (a) and (b) of this sentence below, and to
have satisfied all its other obligations under such Notes and this Indenture
(and the Trustee, on demand of and at the expense of the Issuers, shall execute
proper instruments acknowledging the same), except for the following provisions
which shall survive until otherwise terminated or discharged hereunder: (a) the
rights of Holders of outstanding Notes to receive solely from the trust fund
described in Section 8.04 hereof, and as more fully set forth in such
Section, payments in respect of the principal of, premium, if any, and interest
(including Additional Interest, if any) on, such Notes when such payments are
due, (b) the Issuers’ obligations with respect to such Notes under
Sections 2.03, 2.04, 2.06, 2.07, 2.10 and 4.02 hereof, (c) the rights,
powers, trusts, duties and immunities of the Trustee hereunder and the Issuers’
and the Subsidiary Guarantors’ obligations in connection therewith and (d) this
Article 8.  Subject to compliance
with this Article 8, the Issuers may exercise the option under this Section 8.02
notwithstanding the prior exercise of its option under Section 8.03
hereof.

 

Section 8.03.          Covenant Defeasance.

 

Upon the Issuers’ exercise under
Section 8.01 hereof of the option applicable to this Section 8.03,
the Issuers and the Subsidiary Guarantors shall, subject to the satisfaction of
the conditions set forth in Section 8.04 hereof, be released from their
obligations under the covenants contained in Sections 3.09, 4.04, 4.06, 4.07,
4.08, 4.09, 4.10, 4.11, 4.12, 4.13, 4.14, 4.15, 4.16, 4.18 and 5.01(a)(iv) hereof
and any covenant added to this Indenture subsequent to the Issue Date pursuant
to Section 9.01 hereof with respect to the outstanding Notes on and after
the date the conditions set forth below are satisfied (hereinafter, “Covenant
Defeasance”), and the Notes shall thereafter be deemed not “outstanding” for
the purposes of any direction, waiver, consent or declaration or act of Holders
(and the consequences of any thereof) in connection with such covenants, but
shall continue to be deemed “outstanding” for all other purposes hereunder (it
being understood that such Notes shall not be deemed outstanding for accounting
purposes).  For this purpose, Covenant
Defeasance means that, with respect to the outstanding Notes, the Issuers may
omit to comply with and shall have no liability in respect of any term,
condition or limitation set forth in any such covenant, whether directly or
indirectly, by reason of any reference elsewhere herein to any such covenant or
by reason of any reference in any such covenant to any other provision herein
or in any other document and such omission to comply shall not constitute a
Default or an Event of Default under Section 6.01 hereof, but, except as
specified above, the remainder of this Indenture and such Notes shall be
unaffected thereby.  In addition, upon
the Issuers’ exercise under Section 8.01 hereof of the option applicable
to this Section 8.03 hereof, subject to the satisfaction of the conditions
set forth in Section 8.04 hereof, Sections 6.01(d) through 6.01(i) hereof
shall not constitute Events of Default.

 

80

 

Section 8.04.          Conditions to Legal
Defeasance or Covenant Defeasance.

 

The following
shall be the conditions to the application of either Section 8.02 or 8.03
hereof to the outstanding Notes:

 

In order to
exercise either Legal Defeasance or Covenant Defeasance:

 

(a)           the Issuers must irrevocably deposit with
the Trustee, in trust, for the benefit of the Holders, cash in United States
dollars, U.S. Government Obligations, or a combination thereof, in such amounts
as shall be sufficient, in the opinion of a nationally recognized firm of
independent public accountants, to pay the principal of, premium, if any, and
interest, on the outstanding Notes at the Stated Maturity thereof or on the
applicable redemption date, as the case may be, and the Issuers must specify
whether the Notes are being defeased to Stated Maturity or to a particular
redemption date;

 

(b)           in the case of an election under Section 8.02
hereof, the Issuers shall have delivered to the Trustee an Opinion of Counsel
reasonably acceptable to the Trustee confirming that (i) the Partnership
has received from, or there has been published by, the Internal Revenue Service
a ruling or (ii) since the Issue Date, there has been a change in the
applicable federal income tax law, in either case to the effect that, and based
thereon such Opinion of Counsel shall confirm that, the Holders of the
outstanding Notes will not recognize income, gain or loss for federal income
tax purposes as a result of such Legal Defeasance and will be subject to
federal income tax on the same amounts, in the same manner and at the same
times as would have been the case if such Legal Defeasance had not occurred;

 

(c)           in the case of an election under Section 8.03
hereof, the Issuers shall have delivered to the Trustee an Opinion of Counsel
reasonably acceptable to the Trustee confirming that the Holders of the
outstanding Notes will not recognize income, gain or loss for federal income
tax purposes as a result of such Covenant Defeasance and will be subject to
federal income tax on the same amounts, in the same manner and at the same
times as would have been the case if such Covenant Defeasance had not occurred;

 

(d)           no Default or Event of Default shall have
occurred and be continuing either (i) on the date of such deposit (other
than a Default or Event of Default resulting from the incurrence of
Indebtedness all or a portion of the proceeds of which shall be applied to such
deposit) or (ii) insofar as Sections 6.01(j) and 6.01(k) hereof
are concerned, at any time in the period ending on the 91st day after the date
of deposit;

 

(e)           such Legal Defeasance or Covenant Defeasance
shall not result in a breach or violation of, or constitute a default under,
any material agreement or instrument (other than this Indenture) to which the
Partnership or any of its Subsidiaries is a party or by which the Partnership
or any of its Subsidiaries is bound;

 

(f)            the Issuers shall have delivered to the
Trustee an Opinion of Counsel to the effect that after the 91st day following
the deposit, the trust funds will not be subject to the effect of any
applicable bankruptcy, insolvency, reorganization or similar laws affecting
creditors’ rights generally;

 

81

 

(g)           the Issuers shall have delivered to the
Trustee an Officers’ Certificate stating that the deposit was not made by the
Issuers with the intent of preferring the Holders over any other creditors of
the Issuers or the Subsidiary Guarantors or with the intent of defeating,
hindering, delaying or defrauding other creditors of the Issuers; and

 

(h)           the Issuers shall have delivered to the
Trustee an Officers’ Certificate and an Opinion of Counsel, each stating that
all conditions precedent provided for or relating to the Legal Defeasance or
the Covenant Defeasance have been complied with.

 

Section 8.05.          Deposited Money and
Government Securities to be Held in Trust, Other Miscellaneous Provisions.

 

Subject to Section 11.03
hereof, all money and U.S. Government Obligations (including the proceeds
thereof) deposited with the Trustee (or other qualifying trustee, collectively
for purposes of this Section 8.05, the “Trustee”) pursuant to Section 8.04
hereof in respect of the outstanding Notes shall be held in trust and applied
by the Trustee, in accordance with the provisions of such Notes and this
Indenture, to the payment, either directly or through any Paying Agent
(including either Issuer acting as a Paying Agent) as the Trustee may
determine, to the Holders of such Notes of all sums due and to become due
thereon in respect of principal, premium, if any, and interest (including
Additional Interest, if any), but such money need not be segregated from other
funds except to the extent required by law.

 

The Issuers and the Subsidiary
Guarantors shall pay and indemnify the Trustee against any tax, fee or other
charge imposed on or assessed against the cash or non-callable U.S. Government
Obligations deposited pursuant to Section 8.04 hereof or the principal and
interest received in respect thereof other than any such tax, fee or other
charge which by law is for the account of the Holders of the outstanding Notes.

 

Anything in this Article 8
to the contrary notwithstanding, the Trustee shall deliver or pay to the
Issuers from time to time upon the request of the Issuers any money or
non-callable U.S. Government Obligations held by it as provided in Section 8.04
hereof which, in the opinion of a nationally recognized firm of independent
public accountants expressed in a written certification thereof delivered to
the Trustee (which may be the opinion delivered under Section 8.04(a) hereof),
are in excess of the amount thereof that would then be required to be deposited
to effect an equivalent Legal Defeasance or Covenant Defeasance.

 

If the Issuers exercise either
their Legal Defeasance or Covenant Defeasance option, each Subsidiary Guarantor
shall be released and relieved of any obligations under its Guarantee and any
security for the Notes (other than the trust fund described in Section 8.04
hereof) shall be released.

 

Section 8.06.          [Intentionally omitted].

 

Section 8.07.          Reinstatement.

 

If the Trustee or Paying Agent
is unable to apply any United States dollars or U.S. Government Obligations in
accordance with Section 8.02 or 8.03 hereof, as the case may be, by reason
of any legal proceeding or by reason of any order or judgment of any court or

 

82

 

governmental authority enjoining, restraining
or otherwise prohibiting such application, then the Issuers’ and the Subsidiary
Guarantors’ Obligations under this Indenture, the Notes and the Guarantees, as
applicable, shall be revived and reinstated as though no deposit had occurred
pursuant to Section 8.02 or 8.03 hereof until such time as the Trustee or
Paying Agent is permitted to apply all such money or U.S. Government
Obligations in accordance with Section 8.02 or 8.03 hereof, as the case
may be; provided, however, that, if the Issuers or the Subsidiary Guarantors
make any payment of principal of, premium, if any, or interest (including any
Additional Interest, if any) on any Note following the reinstatement of its
Obligations, the Issuers and the Subsidiary Guarantors shall be subrogated to
the rights of the Holders of such Notes to receive such payment from the money
or U.S. Government Obligations held by the Trustee or Paying Agent.

 

ARTICLE 9

AMENDMENT,
SUPPLEMENT AND WAIVER

 

Section 9.01.          Without Consent of
Holders of Notes.

 

Notwithstanding
Section 9.02 of this Indenture, the Issuers and the Subsidiary Guarantors
and the Trustee may amend or supplement this Indenture, the Guarantees, or the
Notes without the consent of any Holder of a Note:

 

(a)           to cure any ambiguity, defect or
inconsistency;

 

(b)           to provide for uncertificated Notes in
addition to or in place of certificated Notes;

 

(c)           to provide for the assumption of an Issuer’s
or a Subsidiary Guarantor’s obligations to the Holders of the Notes in the case
of a merger or consolidation or sale of all or substantially all of such Issuer’s
assets pursuant to Article 5 hereof;

 

(d)           to add or release Subsidiary Guarantors
pursuant to the terms of this Indenture;

 

(e)           to make any change that would provide any
additional rights or benefits to the Holders of the Notes or surrender any
right or power conferred upon the Issuers or the Subsidiary Guarantors by this
Indenture that does not adversely affect the rights hereunder of any Holder of
the Notes, provided that any change to conform this Indenture to the Offering
Memorandum shall not be deemed to adversely affect such rights;

 

(f)            to provide for the issuance of additional
Notes in accordance with the limitations set forth in this Indenture;

 

(g)           to comply with requirements of the SEC in
order to effect or maintain the qualification of this Indenture under the TIA;

 

(h)           to evidence or provide for the acceptance of
appointment under this Indenture of a successor Trustee;

 

(i)            to add any additional Events of Default; or

 

83

 

(j)            to secure the Notes and/or the Guarantees.

 

Upon the request of the Issuers
accompanied by a resolution of the Board of Directors of the General Partner
(in the case of the Partnership), and of the Board of Directors of MarkWest
Finance and each of the Subsidiary Guarantors (in the case of MarkWest Finance
and the Subsidiary Guarantors), authorizing the execution of any such amended
or supplemental Indenture, and upon receipt by the Trustee of the documents
described in Section 9.06 hereof, the Trustee shall join with the Issuers
and each of the Subsidiary Guarantors in the execution of any amended or
supplemental indenture authorized or permitted by the terms of this Indenture
and to make any further appropriate agreements and stipulations that may be
therein contained, but the Trustee shall not be obligated to enter into such
amended or supplemental indenture that affects its own rights, duties or
immunities under this Indenture or otherwise.

 

Section 9.02.          With Consent of Holders
of Notes.

 

Except as provided below in this
Section 9.02, the Issuers, the Subsidiary Guarantors and the Trustee may
amend or supplement this Indenture (including Sections 3.09, 4.06 and 4.07
hereof), the Guarantees, and the Notes with the consent of the Holders of at
least a majority in principal amount of the Notes then outstanding (including,
without limitation, consents obtained in connection with a purchase of, or
tender offer or exchange offer for, the Notes), and, subject to Sections 6.04
and 6.07 hereof, any existing Default or Event of Default or compliance with
any provision of this Indenture, the Guarantees or the Notes may be waived with
the consent of the Holders of a majority in principal amount of the then
outstanding Notes (including consents obtained in connection with a tender
offer or exchange offer for the Notes).

 

Upon the request of the Issuers
accompanied by a resolution of the Board of Directors of the General Partner
(in the case of the Partnership) and of the Board of Directors of MarkWest
Finance and each of the Subsidiary Guarantors (in the case of MarkWest Finance
and each of the Subsidiary Guarantors) authorizing the execution of any such
amended or supplemental indenture, and upon the filing with the Trustee of
evidence satisfactory to the Trustee of the consent of the Holders of Notes as
aforesaid, and upon receipt by the Trustee of the documents described in Section 9.06
hereof, the Trustee shall join with the Issuers and each of the Subsidiary
Guarantors in the execution of such amended or supplemental indenture unless
such amended or supplemental Indenture affects the Trustee’s own rights, duties
or immunities under this Indenture or otherwise, in which case the Trustee may
in its discretion, but shall not be obligated to, enter into such amended or
supplemental indenture.

 

It shall not be necessary for
the consent of the Holders of Notes under this Section 9.02 to approve the
particular form of any proposed amendment, supplement or waiver, but it shall
be sufficient if such consent approves the substance thereof.

 

After an amendment, supplement
or waiver under this Section becomes effective, the Issuers shall mail to
the Holders of Notes affected thereby a notice briefly describing the
amendment, supplement or waiver.  Any
failure of the Issuers to mail such notice, or any defect therein, shall not,
however, in any way impair or affect the validity of any such amended or
supplemental Indenture or waiver. 
Subject to Sections 6.04 and 6.07 hereof, the Holders of a majority in
aggregate principal amount of the Notes then outstanding may waive compliance
in a

 

84

 

particular instance by the Issuers with any
provision of this Indenture or the Notes. 
However, without the consent of each Holder affected, an amendment, supplement
or waiver may not (with respect to any Notes held by a non-consenting Holder):

 

(a)           reduce the principal amount of Notes whose
Holders must consent to an amendment, supplement or waiver;

 

(b)           reduce the principal of or change the fixed
maturity of any Note or alter or waive any of the provisions with respect to
the redemption or repurchase of the Notes, except as provided above with
respect to Sections 3.09, 4.06 and 4.07 hereof;

 

(c)           reduce the rate of or change the time for
payment of interest, including default interest, on any Note;

 

(d)                               waive
a Default or Event of Default in the payment of principal of or premium, if
any, or interest (including Additional Interest, if any) on the Notes (except a
rescission of acceleration of the Notes by the Holders of at least a majority
in principal amount of the then outstanding Notes and a waiver of the payment
default that resulted from such acceleration);

 

(e)           make any Note payable in money other than
that stated in the Notes;

 

(f)            make any change in the provisions of this
Indenture relating to waivers of past Defaults or the rights of Holders of
Notes to receive payments of principal of or premium, if any, or interest on
the Notes (other than as permitted by clause (g) below);

 

(g)           waive a redemption or repurchase payment
with respect to any Note (other than a payment required by the covenants
contained in Sections 3.09, 4.06 and 4.07 hereof);

 

(h)                               except
as otherwise permitted by this Indenture, release any Subsidiary Guarantor from
any of its Obligations under its Guarantee or this Indenture, or change any
Guarantee in any manner that would adversely affect the right of Holders; or

 

(i)                                  make
any change in Section 6.04 or 6.07 hereof or in the foregoing amendment,
supplement and waiver provisions (except to increase any percentage set forth
therein).

 

Section 9.03.                          Compliance
with Trust Indenture Act.

 

Every amendment or supplement to
this Indenture, the Guarantees, or the Notes shall be set forth in an amended
or supplemental Indenture that complies with the TIA as then in effect.

 

Section 9.04.                          Revocation
and Effect of Consents.

 

Until an amendment, supplement
or waiver becomes effective, a consent to it by a Holder of a Note is a
continuing consent by the Holder of a Note and every subsequent Holder of a Note
or portion of a Note that evidences the same debt as the consenting Holder’s
Note, even if notation of the consent is not made on any Note.  However, any such Holder of a Note or
subsequent Holder of a Note may revoke the consent as to its Note if the Trustee
receives written notice of revocation before the date the waiver, supplement or
amendment becomes effective.

 

85

 

An amendment, supplement or waiver becomes
effective in accordance with its terms and thereafter binds every Holder.

 

The Issuers may, but shall not
be obligated to, fix a record date for the purpose of determining the Holders
entitled to consent to any amendment, supplement or waiver.  If a record date is fixed, then
notwithstanding the last sentence of the immediately preceding paragraph, those
Persons who were Holders at such record date (or their duly designated
proxies), and only those Persons, shall be entitled to consent to such
amendment, supplement or waiver or revoke any consent previously given, whether
or not such Persons continue to be Holders after such record date.  No consent shall be valid or effective for
more than 90 days after such record date except to the extent that the
requisite number of consents to the amendment, supplement or waiver have been
obtained within such 90-day period or as set forth in the next paragraph of
this Section 9.04.

 

After an amendment, supplement
or waiver becomes effective, it shall bind every Holder, unless it makes a
change described in any of clauses (a) through (i) of Section 9.02,
in which case, the amendment, supplement or waiver shall bind only each Holder
of a Note who has consented to it and every subsequent Holder of a Note or
portion of a Note that evidences the same indebtedness as the consenting Holder’s
Note.

 

Section 9.05.          Notation or Exchange of
Notes.

 

The Trustee may place an
appropriate notation about an amendment, supplement or waiver on any Note
thereafter authenticated.  The Issuers in
exchange for all Notes may issue and the Trustee shall authenticate new Notes
(accompanied by a notation of the Guarantees duly endorsed by the Subsidiary
Guarantors) that reflect the amendment, supplement or waiver.  Failure to make the appropriate notation or
issue a new Note shall not affect the validity and effect of such amendment,
supplement or waiver.

 

Section 9.06.          Trustee to Sign
Amendments, Etc.

 

The Trustee shall sign any
amended or supplemental Indenture authorized pursuant to this Article 9 if
the amendment or supplement does not adversely affect the rights, duties,
liabilities or immunities of the Trustee. 
In executing any amended or supplemental indenture, the Trustee shall be
entitled to receive and (subject to Section 7.01) shall be fully protected
in relying upon, an Officers’ Certificate of the Partnership and an Opinion of
Counsel stating that the execution of such amended or supplemental indenture is
authorized or permitted by this Indenture and that all conditions precedent
have been satisfied.

 

Section 9.07.          Effect of Supplemental
Indentures.

 

Upon the execution of any
supplemental indenture under this Article 9, this Indenture shall be
modified in accordance therewith, and such supplemental indenture shall form a
part of this Indenture for all purposes; and every Holder of Notes theretofore
or thereafter authenticated and delivered hereunder shall be bound
thereby.  After a supplemental indenture
becomes effective, the Issuers shall mail to Holders a notice briefly
describing such amendment.  The failure
to give such notice to all Holders, or any defect therein, shall not impair or
affect the validity of an amendment under this Section.

 

86

 

ARTICLE 10

GUARANTEES

 

Section 10.01.        Guarantees.

 

Subject to the provisions of
this Article 10, each of the Subsidiary Guarantors hereby, jointly and
severally, unconditionally guarantees to each Holder of a Note authenticated
and delivered by the Trustee and to the Trustee and its successors and assigns,
irrespective of the validity and enforceability of this Indenture, the Notes or
the other Obligations of the Issuers hereunder or thereunder, that: (a) the
principal of, premium and interest (including Additional Interest, if any) on
the Notes shall be promptly paid in full when due, whether at the maturity or
interest payment or mandatory redemption date, by acceleration, redemption or
otherwise, and interest on the overdue principal of, premium and interest
(including Additional Interest, if any) on the Notes, if any, to the extent
lawful, and all other Obligations of the Issuers to the Holders or the Trustee
under this Indenture and the Notes shall be promptly paid in full or performed,
all in accordance with the terms of this Indenture and the Notes; and (b) in
case of any extension of time of payment or renewal of any Notes or any of such
other Obligations, that same shall be promptly paid in full when due or
performed in accordance with the terms of the extension or renewal, subject to
any applicable grace period, whether at Stated Maturity, by acceleration or
otherwise.  Failing payment when so due
of any amount so guaranteed or any performance so guaranteed for whatever
reason, the Subsidiary Guarantors shall be jointly and severally obligated to
pay the same immediately.  The Subsidiary
Guarantors hereby agree that to the fullest extent permitted by applicable law,
their obligations hereunder shall be unconditional, irrespective of the
validity, regularity or enforceability of the Notes or this Indenture, the
absence of any action to enforce the same, any waiver or consent by any Holder
of the Notes with respect to any provisions of this Indenture and the Notes,
the recovery of any judgment against the Issuers, any action to enforce the
same or any other circumstance (other than complete performance) which might
otherwise constitute a legal or equitable discharge or defense of a Subsidiary
Guarantor.  To the fullest extent
permitted by applicable law, each Subsidiary Guarantor hereby waives diligence,
presentment, demand of payment, filing of claims with a court in the event of
insolvency or bankruptcy of the Issuers, any right to require a proceeding
first against the Issuers, protest, notice and all demands whatsoever and
covenants that its Guarantee shall not be discharged except by complete
performance of the obligations contained in the Notes and this Indenture.

 

If any Holder or the Trustee is
required by any court or otherwise to return to the Issuers or Subsidiary
Guarantors, or any custodian, trustee, liquidator or other similar official
acting in relation to either the Issuers or Subsidiary Guarantors, any amount
paid by any of them to the Trustee or such Holder, these Guarantees, to the
extent theretofore discharged, shall be reinstated in full force and effect.  Each Subsidiary Guarantor agrees that it
shall not be entitled to any right of subrogation in relation to the Holders in
respect of any Obligations guaranteed hereby until payment in full of all
Obligations guaranteed hereby.

 

Each Subsidiary Guarantor
further agrees that, as between the Subsidiary Guarantors, on the one hand, and
the Holders and the Trustee, on the other hand, (x) the maturity of the
Obligations guaranteed hereby may be accelerated as provided in Article 6
hereof for the purposes of these Guarantees, notwithstanding any stay,
injunction or other prohibition

 

87

 

preventing such acceleration in respect of the
Obligations guaranteed hereby, and (y) in the event of any declaration of
acceleration of such Obligations as provided in Article 6 hereof, such
Obligations (whether or not due and payable) shall forthwith become due and
payable by the Subsidiary Guarantors for the purpose of these Guarantees.  The Subsidiary Guarantors shall have the
right to seek contribution from any non-paying Subsidiary Guarantor so long as
the exercise of such right does not impair the rights of the Holders under
these Guarantees.

 

Section 10.02.        Limitation of Guarantor’s
Liability.

 

Each Subsidiary Guarantor and,
by its acceptance hereof, each Holder hereby confirms that it is its intention
that the Guarantee by such Subsidiary Guarantor not constitute a fraudulent
transfer or conveyance for purposes of the Bankruptcy Law, the Uniform
Fraudulent Conveyance Act, the Uniform Fraudulent Transfer Act or any similar
federal or state law to the extent applicable to the Guarantees.  To effectuate the foregoing intention, each
such Person hereby irrevocably agrees that the Obligation of such Subsidiary
Guarantor under its Guarantee under this Article 10 shall be limited to
the maximum amount as shall, after giving effect to such maximum amount and all
other (contingent or otherwise) liabilities of such Subsidiary Guarantor that
are relevant under such laws, and after giving effect to any rights to contribution
of such Subsidiary Guarantor pursuant to any agreement providing for an
equitable contribution among such Subsidiary Guarantor and other Affiliates of
the Issuers of payments made by guarantees by such parties, result in the
Obligations of such Subsidiary Guarantor in respect of such maximum amount not
constituting a fraudulent conveyance. 
Each Holder, by accepting the benefits hereof, confirms its intention
that, in the event of bankruptcy, reorganization or other similar proceeding of
either of the Issuers or any Subsidiary Guarantor in which concurrent claims
are made upon such Subsidiary Guarantor hereunder, to the extent such claims
shall not be fully satisfied, each such claimant with a valid claim against
such Issuer shall be entitled to a ratable share of all payments by such
Subsidiary Guarantor in respect of such concurrent claims.

 

Section 10.03.        Execution and Delivery of
Notations of Guarantees.

 

To evidence the Guarantees set
forth in Section 10.01 hereof, each Subsidiary Guarantor hereby agrees
that a notation of the Guarantees substantially in the form of Exhibit D
shall be endorsed on each Note authenticated and delivered by the Trustee and
that this Indenture shall be executed on behalf of such Subsidiary Guarantor by
one of its Officers.

 

Each Subsidiary Guarantor hereby
agrees that the Guarantees set forth in Section 10.01 shall remain in full
force and effect notwithstanding any failure to endorse on each Note a notation
of the Guarantees.  If an Officer whose
signature is on this Indenture or on the notation of Guarantees no longer holds
that office at the time the Trustee authenticates the Note on which the
notation of the Guarantees is endorsed, the Guarantees shall be valid
nevertheless.

 

The delivery of any Note by the
Trustee, after the authentication thereof hereunder, shall constitute due
delivery of the Guarantees set forth in this Indenture on behalf of the
Subsidiary Guarantors.

 

88

 

Section 10.04.                [Intentionally
omitted].

 

Section 10.05.                Releases.

 

Concurrently with any sale of
assets (including, if applicable, all of the Equity Interests of any Subsidiary
Guarantor), any Liens in favor of the Trustee in the assets sold thereby shall
be released; provided that in the event of an Asset Sale, the Net Proceeds from
such sale or other disposition are treated in accordance with the provisions of
Section 4.07 hereof.  The Guarantee
and all other obligations under this Indenture of a Subsidiary Guarantor will
be released:  (i) in connection with
any sale or other disposition of all or substantially all of the assets of such
Subsidiary Guarantor (including by way of merger or consolidation) to a Person
that is not (either before or after giving effect to such transaction) a Restricted
Subsidiary, if the Partnership applies the Net Proceeds of that sale or other
disposition in accordance with Section 4.07 hereof; or (ii) in
connection with any sale or other disposition of all of the Equity Interests of
a Subsidiary Guarantor to a Person that is not (either before or after giving
effect to such transaction) a Restricted Subsidiary, if the Partnership applies
the Net Proceeds of that sale in accordance with Section 4.07 hereof; or (iii) if
the Partnership designates any Restricted Subsidiary that is a Subsidiary
Guarantor as an Unrestricted Subsidiary; or (iv) upon Legal Defeasance or
Covenant Defeasance pursuant to Article 8 hereof or upon satisfaction and
discharge of this Indenture pursuant to Article 11 hereof;  or (v) in the case of any Subsidiary Guarantor other
than the Operating Company, at such time as such Subsidiary Guarantor ceases to
guarantee any other Indebtedness of either of the Issuers and any Indebtedness
of the Operating Company; or (vi) in the case of the Operating Company, at
such time as the Operating Company ceases to guarantee any other Indebtedness
of either of the Issuers, provided that it is then no longer an obligor with
respect to any Indebtedness under any Credit Facility.  Upon delivery by the Partnership to the
Trustee of an Officers’ Certificate to the effect that such sale or other
disposition was made by the Partnership in accordance with the provisions of
this Indenture, including without limitation Section 4.07 hereof, or such
Guarantee is to be released pursuant to the provisions of the immediately
preceding sentence, the Trustee shall execute any documents reasonably required
in order to evidence the release of any Subsidiary Guarantor from all of its
obligations under its Guarantee and this Indenture.  Any Subsidiary Guarantor not released from its
obligations under its Guarantee shall remain liable for the full amount of
principal of and interest on the Notes and for the other obligations of any
Subsidiary Guarantor under this Indenture as provided in this Article 10.

 

Section 10.06.        “Trustee” to Include
Paying Agent.

 

In case at any time any Paying
Agent other than the Trustee shall have been appointed by the Issuers and be
then acting hereunder, the term “Trustee” as used in this Article 10 shall
in such case (unless the context shall otherwise require) be construed as
extending to and including such Paying Agent within its meaning as fully and
for all intents and purposes as if such Paying Agent were named in this Article 10
in place of the Trustee.

 

89

 

ARTICLE 11

SATISFACTION
AND DISCHARGE

 

Section 11.01.        Satisfaction and
Discharge.

 

This Indenture shall upon the
request of the Issuers cease to be of further effect (except as to surviving
rights of registration of transfer or exchange of Notes herein expressly
provided for, the Issuers’ obligations under Section 7.07 hereof, the
Issuers’ rights of optional redemption under Article 3 hereof, and the
Trustee’s and the Paying Agent’s obligations under Section 11.02 and 11.03
hereof) and the Trustee, at the expense of the Issuers, shall execute proper
instruments acknowledging satisfaction and discharge of this Indenture when

 

(a)           either

 

(i)            all Notes theretofore
authenticated and delivered (other than (A) Notes which have been
destroyed, lost or stolen and which have been replaced or paid as provided in Section 2.07
and (B) Notes for whose payment money has been deposited in trust with the
Trustee or any Paying Agent and thereafter paid to the Issuers or discharged
from such trust) have been delivered to the Trustee for cancellation; or

 

(ii)           all such Notes not
theretofore delivered to the Trustee for cancellation

 

(A)          have become due and
payable; or

 

(B)           shall become due and
payable at their Stated Maturity within one year by reason of the mailing of a
notice of redemption or otherwise, or

 

(C)           are to be called for
redemption within one year under arrangements satisfactory to the Trustee for
the giving of notice of redemption by the Trustee in the name, and at the
expense, of the Issuers,

 

and the Issuers or any
Subsidiary Guarantor, in the case of clause (A), (B) or (C) above,
has irrevocably deposited or caused to be deposited with the Trustee as trust
funds in trust for the benefit of the Holders, cash in U.S. dollars, U.S.
Government Obligations or a combination of cash in U.S. dollars and U.S.
Government Obligations, in amounts as will be sufficient without consideration
of any reinvestment of interest, to pay and discharge the entire indebtedness
on the Notes not delivered to the Trustee for cancellation for principal,
premium, if any, and accrued interest to the date of fixed maturity or
redemption;

 

(b)           no Default or Event of Default shall have
occurred and be continuing on the date of such deposit or will occur as a
result of such deposit and such deposit will not result in a breach or
violation of, or constitute a default under, any material agreement or
instrument (other than this Indenture) to which the Partnership or any of its
Subsidiaries is a party or by which the Partnership or any of its Subsidiaries
is bound; and

 

(c)           the Issuers or any Subsidiary Guarantor has
paid or caused to be paid all sums then due and payable hereunder by the
Issuers;

 

90

 

(d)           the Issuers have delivered irrevocable
instructions to the Trustee to apply the deposited money toward the payment of
the Notes at fixed maturity or the redemption date, as the case may be; and

 

(e)           the Issuers have delivered to the Trustee an
Officers’ Certificate and an Opinion of Counsel, each stating that all
conditions precedent herein provided for relating to the satisfaction and
discharge of this Indenture (“Discharge”) have been satisfied.

 

Notwithstanding the satisfaction
and discharge of this Indenture, the Issuers’ obligations in Sections 2.03,
2.04, 2.06, 2.07, 2.11, 7.07, 7.08, 11.02, 11.03 and 11.04, and the Trustee’s
and Paying Agent’s obligations in Section 11.03 shall survive until the
Notes are no longer outstanding. 
Thereafter, only the Issuers’ obligations in Section 11.03 shall
survive.

 

In order to have money available
on a payment date to pay principal (and premium, if any, on) or interest on the
Notes, the U.S. Government Obligations shall be payable as to principal (and
premium, if any) or interest at least one Business Day before such payment date
in such amounts as shall provide the necessary money.  The U.S. Government Obligations shall not be
callable at the issuer’s option.

 

Section 11.02.        Application of Trust.

 

All money deposited with the
Trustee pursuant to Section 11.01 shall be held in trust and, at the
written direction of the Issuers, be invested prior to maturity in U.S.
Government Obligations, and applied by the Trustee in accordance with the
provisions of the Notes and this Indenture, to the payment, either directly or
through any Paying Agent as the Trustee may determine, to the Persons entitled
thereto, of the principal (and premium, if any) and interest for the payment of
which money has been deposited with the Trustee; but such money need not be
segregated from other funds except to the extent required by law.

 

Section 11.03.        Repayment of the Issuers.

 

The Trustee and the Paying Agent
shall promptly pay to the Issuers upon written request any excess money or
securities held by them at any time.

 

Subject to applicable escheat
laws, the Trustee and the Paying Agent shall notify the Issuers of, and pay to
the Issuers upon written request, any money held by them for the payment of
principal or interest that remains unclaimed for two years after the date upon
which such payment shall have become due; provided that the Issuers shall have
either caused notice of such payment to be mailed to each Holder of the Notes
entitled thereto no less than 30 days prior to such repayment or within such
period shall have published such notice in a financial newspaper of widespread
circulation published in The City of New York, including, without limitation, The Wall Street Journal (national
edition).  After payment to the Issuers,
Holders entitled to the money must look to the Issuers for payment as general
creditors unless an applicable abandoned property law designates another
Person, and all liability of the Trustee and such Paying Agent with respect to
such money shall cease.  In the absence
of a written request from the Issuers to return unclaimed funds to the Issuers,
the Trustee shall from time to time deliver all unclaimed funds to or as
directed by applicable escheat authorities, as determined by the Trustee in its
sole discretion, in accordance with the customary practices and procedures of
the Trustee.

 

91

 

Section 11.04.        Reinstatement.

 

If the Trustee or Paying Agent
is unable to apply any money or U.S. Government Obligations in accordance with Section 11.01
by reason of any legal proceeding or by reason of any order or judgment of any
court of governmental authority enjoining, restraining or otherwise prohibiting
such application, the Issuers’ and Subsidiary Guarantors’ Obligations under
this Indenture, the Notes and the Guarantees, as applicable, shall be revived
and reinstated as though no deposit has occurred pursuant to Section 11.01
until such time as the Trustee or Paying Agent is permitted to apply all such
money or U.S. Government Obligations in accordance with Section 11.02,
provided, however, that if the Issuers or the Subsidiary Guarantors have made
any payment of interest or premium, if any, on or principal of any Notes
because of the reinstatement of their Obligations, the Issuers or such
Subsidiary Guarantors shall be subrogated to the rights of the Holders of such
Notes to receive such payment from the money or U.S. Government Obligations
held by the Trustee or Paying Agent.

 

ARTICLE 12

MISCELLANEOUS

 

Section 12.01.        Trust Indenture Act
Controls.

 

If any provision of this
Indenture limits, qualifies or conflicts with the duties imposed by TIA Section 318(c),
the imposed duties shall control.

 

Section 12.02.        Notices.

 

Any notice or communication by
the Issuers or the Trustee to the others is duly given if in writing (in the
English language) and delivered in person or mailed by first class mail
(registered or certified, return receipt requested), telecopier or overnight
air courier guaranteeing next day delivery, to the others’ address:

 

If to the
Issuers or any Subsidiary Guarantor:

 

MarkWest Energy
Partners, L.P.

1515 Arapahoe
St., Tower II, Suite 700

Denver,
Colorado  80202

Attention: Chief Financial
Officer

 

With a copy to:

 

Vinson &
Elkins L.L.P.

2300 First City
Tower

1001 Fannin St.

Houston,
Texas  77002

Telecopier No.:
(713) 615-5861

Attention: David P. Oelman, Esq.

 

92

 

If to the
Trustee or Paying Agent:

 

Wells Fargo
Bank, National Association

1445 Ross
Avenue – Second Floor

Dallas,
Texas  75202-2812

Attention:  Corporate Trust Department

Telecopier No.:  (214) 777-4086

 

The Issuers, any Subsidiary
Guarantor or the Trustee, by notice to the others may designate additional or
different addresses for subsequent notices or communications.

 

All notices and communications
(other than those sent to Holders) 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 sent by facsimile transmission; and the next Business Day
after timely delivery to the courier, if sent by overnight air courier
guaranteeing next day delivery.

 

Any notice or communication to a
Holder shall be mailed by first class mail, certified or registered, return
receipt requested, or by overnight air courier guaranteeing next day delivery
to its address shown on the register kept by the Registrar.  Any notice or communication shall also be so
mailed to any Person described in TIA Section 313(c), to the extent
required by the TIA.  Failure to mail a
notice or communication to a Holder or any defect in it shall not affect its
sufficiency with respect to other Holders.

 

If a notice or communication is
mailed in the manner provided above within the time prescribed, it is duly
given, whether or not the addressee receives it.

 

If either of the Issuers mails a
notice or communication to Holders, it shall mail a copy to the Trustee and
each Agent at the same time.

 

Section 12.03.        Communication by Holders
of Notes with Other Holders of Notes.

 

The Trustee is subject to TIA Section 312(b),
and Holders may communicate pursuant thereto with other Holders with respect to
their rights under this Indenture or the Notes. 
The Issuers, the Subsidiary Guarantors, the Trustee, the Registrar and
anyone else shall have the protection of TIA Section 312(c).

 

Section 12.04.        Certificate and Opinion as
to Conditions Precedent.

 

Upon any request or application
by the Issuers or any Subsidiary Guarantor to the Trustee to take any action
under this Indenture, the Issuers or such Subsidiary Guarantors shall furnish
to the Trustee:

 

(a)           an Officers’ Certificate in form and
substance reasonably satisfactory to the Trustee (which shall include the statements
set forth in Section 12.05 hereof) stating that, in the opinion of the
signers, all conditions precedent and covenants, if any, provided for in this
Indenture relating to the proposed action have been satisfied; and

 

93

 

(b)           an Opinion of Counsel in form and substance
reasonably satisfactory to the Trustee (which shall include the statements set
forth in Section 12.05 hereof) stating that, in the opinion of such
counsel, all such conditions precedent and covenants have been satisfied.

 

In any case where several
matters are required to be certified by, or covered by an opinion of, any
specified Person, it is not necessary that all such matters be certified by, or
covered by the opinion of, only one such Person, or that they be so certified
or covered by only one document, but one such Person may certify or give an
opinion with respect to some matters and one or more such Persons as to other
matters, and any such Person may certify or give an opinion as to such matters
in one or several documents.

 

Any certificate or opinion of an
Officer of the General Partner, an Issuer or any Subsidiary Guarantor may be
based, insofar as it relates to legal matters, upon a certificate or opinion
of, or representations by, counsel, unless such Officer knows, or in the
exercise of reasonable care should know, that the certificate or opinion or
representations with respect to the matters upon which his certificate or
opinion is based are erroneous.  Any such
certificate or Opinion of Counsel may be based, and may state that it is so
based, insofar as it relates to factual matters, upon a certificate or opinion
of, or representations by, an Officer or Officers of the General Partner, an
Issuer or such Subsidiary Guarantor stating that the information with respect
to such factual matters is in possession of the General Partner, an Issuer or
such Subsidiary Guarantor, unless such counsel knows, or in the exercise of
reasonable care should know, that the certificate of opinion or representations
with respect to such matters are erroneous.

 

Where any Person is required to
make, give or execute two or more applications, requests, consents,
certificates, statements, opinions or other instruments under this Indenture,
they may, but need not, be consolidated and form one instrument.

 

Section 12.05.        Statements Required in
Certificate or Opinion.

 

Each certificate or opinion with
respect to compliance with a condition or covenant provided for in this
Indenture (other than a certificate provided pursuant to TIA Section 314(a)(4))
shall comply with the provisions of TIA Section 314(e) and shall
include:

 

(a)           a statement that the person making such
certificate or opinion has read such covenant or condition;

 

(b)           a brief statement as to the nature and scope
of the examination or investigation upon which the statements or opinions
contained in such certificate or opinion are based;

 

(c)           a statement that, in the opinion of such
person, he or she has made such examination or investigation as is necessary to
enable him or her to express an informed opinion as to whether or not such
covenant or condition has been satisfied; and

 

(d)           a statement as to whether or not, in the
opinion of such person, such condition or covenant has been complied with.

 

94

 

Section 12.06.        Rules by Trustee and
Agents.

 

The Trustee may make reasonable rules for
action by or at a meeting of Holders. 
The Registrar or Paying Agent may make reasonable rules and set
reasonable requirements for its functions.

 

Section 12.07.        No Personal Liability of
Directors, Officers, Employees and Unitholders and No Recourse Against General
Partner.

 

No past, present or future
director, officer, partner, employee, incorporator, manager or unitholder or
other owner of Equity Interests of the Issuers, the General Partner or any
Subsidiary Guarantor, as such, shall have any liability for any Obligations of
the Issuers or the Subsidiary Guarantors under the Notes, this Indenture or the
Guarantees or for any claim based on, in respect of, or by reason of, such
Obligations or their creation.  Each
Holder by accepting a Note waives and releases all such liability.  The waiver and release are part of the
consideration for issuance of the Notes.

 

Section 12.08.        Governing Law.

 

THE LAWS OF THE STATE OF NEW
YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS INDENTURE, THE NOTES AND THE
GUARANTEES.

 

Section 12.09.        No Adverse Interpretation
of Other Agreements.

 

This Indenture may not be used
to interpret any other indenture, loan or debt agreement of either of the
Issuers or any Subsidiary of the Partnership or of any other Person.  Any such indenture, loan or debt agreement
may not be used to interpret this Indenture or the Guarantees.

 

Section 12.10.        Successors.

 

All agreements of the Issuers
and the Subsidiary Guarantors in this Indenture, the Notes and the Guarantees
shall bind their respective successors. 
All agreements of the Trustee in this Indenture shall bind its successors.

 

Section 12.11.        Severability.

 

In case any provision in this
Indenture, the Notes or the Guarantees shall be invalid, illegal or
unenforceable, the validity, legality and enforceability of the remaining
provisions shall not in any way be affected or impaired thereby.

 

Section 12.12.        Counterpart Originals.

 

The parties may sign any number
of copies of this Indenture.  Each signed
copy shall be an original, but all of them together represent the same
agreement.

 

95

 

Section 12.13.        Table of Contents,
Headings, Etc.

 

The Table of Contents,
Cross-Reference Table and headings of the Articles and Sections of this
Indenture have been inserted for convenience of reference only, are not to be
considered a part of this Indenture and shall in no way modify or restrict any
of the terms or provisions hereof.

 

[Signatures on following pages]

 

96

 

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

 

Issuers:

 

	
  MARKWEST ENERGY PARTNERS, L.P.

  	
   

  
	
   

  	
   

  
	
  By:

  	
  MARKWEST ENERGY GP, L.L.C., its general
  partner

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   /s/
  Andrew L. Schroeder

  	
   

  
	
   

  	
  Name:  Andrew L. Schroeder

  	
   

  
	
   

  	
  Title:  Vice President Finance, Treasurer and
  Assistant Secretary

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  MARKWEST ENERGY FINANCE CORPORATION

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:

  	
   /s/
  Andrew L. Schroeder

  	
   

  	
   

  
	
  Name:  Andrew L. Schroeder

  	
   

  
	
  Title:  Vice President Finance, Treasurer and
  Assistant Secretary

  	
   

  
						

 

97

 

	
   

  	
  Subsidiary
  Guarantors:

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  HYDROCARBON, INC.

  
	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  ENERGY GP, L.L.C.

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MASON
  PIPELINE LIMITED LIABILITY COMPANY

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MARKWEST
  HYDROCARBON, INC.

  
	
   

  	
   

  	
  its
  Sole Member

  	
   

  
	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  

 

98

 

	
   

  	
  BASIN
  PIPELINE 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  ENERGY APPALACHIA, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  ENERGY EAST TEXAS GAS

  
	
   

  	
  COMPANY,
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
						

 

99

 

	
   

  	
  MARKWEST
  BLACKHAWK, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  GAS SERVICES, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST
  JAVELINA COMPANY, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
					

 

100

 

	
   

  	
  MARKWEST
  JAVELINA PIPELINE COMPANY, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  LIBERTY GAS GATHERING, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  MICHIGAN PIPELINE 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
					

 

101

 

	
   

  	
  MARKWEST
  NEW MEXICO, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  PINNACLE, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  MARKWEST
  PIONEER, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
							

 

102

 

	
   

  	
  MARKWEST
  PIPELINE COMPANY, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST
  POWER TEX, 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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
					

 

103

 

	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  

 

104

 

	
   

  	
  MATREX,
  L.L.C.

  
	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  Basin
  Pipeline L.L.C.

  
	
   

  	
   

  	
   

  	
  its
  Sole Member and Manager

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
  Name:

  	
  Andrew L. Schroeder

  
	
   

  	
  Title:

  	
  Vice
  President Finance, Treasurer and Assistant Secretary

  

 

105

 

	
   

  	
  Trustee:

  
	
   

  	
   

  	
   

  
	
   

  	
  WELLS
  FARGO BANK, NATIONAL

  
	
   

  	
  ASSOCIATION, as
  Trustee

  
	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ Patrick Giordano

  
	
   

  	
  Name: Patrick Giordano

  
	
   

  	
  Title: Vice President

  

 

1

 

SCHEDULE A

 

Schedule of Subsidiary Guarantors

 

	
  MarkWest
  Energy Operating Company, L.L.C.

  
	
   

  
	
  MarkWest
  Hydrocarbon, Inc.

  
	
   

  
	
  MarkWest
  Energy GP, L.L.C.

  
	
   

  
	
  Basin
  Pipeline L.L.C. 

  
	
   

  
	
  MarkWest
  Blackhawk, L.L.C.

  
	
   

  
	
  MarkWest
  Energy Appalachia, L.L.C.

  
	
   

  
	
  MarkWest
  Energy East Texas Gas Company, L.L.C.

  
	
   

  
	
  MarkWest Gas
  Services, L.L.C.

  
	
   

  
	
  MarkWest
  Javelina Company, L.L.C.

  
	
   

  
	
  MarkWest
  Javelina Pipeline Company, L.L.C.

  
	
   

  
	
  MarkWest
  Michigan Pipeline Company, 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.

  
	
   

  
	
  MarkWest
  Oklahoma Gas Company, L.L.C.

  
	
   

  
	
  Mason
  Pipeline Limited Liability Company

  
	
   

  
	
  Matrex,
  L.L.C.

  
	
   

  
	
  MarkWest
  Liberty Gas Gathering, L.L.C.

  
	
   

  
	
  West Shore
  Processing Company, L.L.C.

  

 

2

 

EXHIBIT A

 

(Face of Note)

 

THIS GLOBAL NOTE IS HELD BY THE DEPOSITARY (AS
DEFINED IN THE INDENTURE GOVERNING THIS NOTE) OR ITS NOMINEE IN CUSTODY FOR THE
BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON
UNDER ANY CIRCUMSTANCES EXCEPT THAT (I) THE TRUSTEE MAY MAKE SUCH
NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO SECTION 2.06 OF THE
INDENTURE, (II) THIS GLOBAL NOTE MAY BE EXCHANGED PURSUANT TO SECTION 2.06(a) OF
THE INDENTURE, (III) THIS GLOBAL NOTE MAY BE DELIVERED TO THE TRUSTEE
FOR CANCELLATION PURSUANT TO SECTION 2.11 OF THE INDENTURE AND (IV) THIS
GLOBAL NOTE MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITARY WITH THE PRIOR
WRITTEN CONSENT OF THE ISSUERS.(1)

 

UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR
IN PART FOR NOTES IN DEFINITIVE FORM, THIS NOTE MAY NOT BE
TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY
OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE
DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY
OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY. 
UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF
THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (“DTC”), TO
THE ISSUERS OR THEIR AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR
SUCH OTHER NAME AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC
(AND ANY PAYMENT IS MADE TO CEDE & CO. OR SUCH OTHER ENTITY AS MAY BE
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR
OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL
INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN. 1

 

THIS SECURITY HAS NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR THE
SECURITIES LAWS OF ANY STATE OR OTHER JURISDICTION.  NEITHER THIS SECURITY NOR ANY INTEREST OR
PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED,
PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH
REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO, SUCH
REGISTRATION.  THE HOLDER OF THIS
SECURITY, BY ITS ACCEPTANCE HEREOF, AGREES ON ITS OWN BEHALF AND ON BEHALF OF
ANY INVESTOR ACCOUNT FOR WHICH IT HAS PURCHASED SECURITIES, TO OFFER, SELL OR
OTHERWISE TRANSFER SUCH SECURITY, PRIOR

 

(1) This is included in Global Notes
only.

 

1

 

TO THE DATE (THE “RESALE RESTRICTION
TERMINATION DATE”) THAT IS [IN THE CASE OF NOTES SOLD IN RELIANCE ON RULE 144A
UNDER THE SECURITIES ACT:  ONE
YEAR] [IN THE CASE OF NOTES SOLD IN RELIANCE ON REGULATION
S UNDER THE SECURITIES ACT: 40 DAYS] AFTER THE LATER OF THE ORIGINAL
ISSUE DATE HEREOF AND THE LAST DATE ON WHICH EITHER ISSUER OR ANY AFFILIATE OF
EITHER ISSUER WAS THE OWNER OF THIS SECURITY (OR ANY PREDECESSOR OF SUCH
SECURITY), ONLY (A) TO AN ISSUER OR ITS SUBSIDIARY, (B) PURSUANT TO A
REGISTRATION STATEMENT THAT HAS BEEN DECLARED EFFECTIVE UNDER THE SECURITIES
ACT, (C) FOR SO LONG AS THE SECURITIES ARE ELIGIBLE FOR RESALE PURSUANT TO
RULE 144A UNDER THE SECURITIES ACT, TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED
INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT THAT
PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL
BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON
RULE 144A, (D) PURSUANT TO OFFERS AND SALES THAT OCCUR OUTSIDE THE UNITED
STATES WITHIN THE MEANING OF REGULATION S UNDER THE SECURITIES ACT, (E) TO
AN INSTITUTIONAL “ACCREDITED INVESTOR” WITHIN THE MEANING OF RULE 501(a)(1),
(2), (3) OR (7) UNDER THE SECURITIES ACT THAT IS AN INSTITUTIONAL
ACCREDITED INVESTOR ACQUIRING THE SECURITY FOR ITS OWN ACCOUNT OR FOR THE
ACCOUNT OF SUCH AN INSTITUTIONAL ACCREDITED INVESTOR, IN EACH CASE IN A MINIMUM
PRINCIPAL AMOUNT OF THE SECURITIES OF $250,000, FOR INVESTMENT PURPOSES AND NOT
WITH A VIEW TO OR FOR OFFER OR SALE IN CONNECTION WITH ANY DISTRIBUTION IN
VIOLATION OF THE SECURITIES ACT, OR (F) PURSUANT TO ANOTHER AVAILABLE
EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT, SUBJECT TO
THE ISSUERS’ AND THE TRUSTEE’S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER
PURSUANT TO CLAUSES (C), (D), (E) OR (F) TO REQUIRE THE DELIVERY OF
AN OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION SATISFACTORY TO
EACH OF THEM.  THIS LEGEND WILL BE
REMOVED UPON THE REQUEST OF THE HOLDER AFTER THE RESALE RESTRICTION TERMINATION
DATE.(2)

 

	
   

  	
   

  	
  CUSIP: 

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  83⁄4% [Series A] [Series B] Senior
  Notes due 2018

  
	
   

  
	
  No.

  	
   

  	
   

  	
   

  	
  $

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  MARKWEST ENERGY PARTNERS, L.P.

  
	
  and

  
	
  MARKWEST ENERGY FINANCE CORPORATION

  
							

 

(2) Legend appears only on the Series A
Notes

 

2

 

promise to pay to                            
or registered assigns, the principal sum of                            
Dollars of the United States of America [or such greater or lesser amount as
may from time to time be endorsed on the Schedule of Exchanges of Interests in
the Global Note](3) on April 15, 2018.

 

Interest Payment Dates: April 15 and October 15
of each year

 

Record Dates: April 1 and October 1

 

Reference is hereby made to the
further provisions of this Note set forth on the reverse hereof, which further
provisions shall for all purposes have the same effect as if set forth at this
place.

 

Unless the certificate of
authorization hereon has been duly executed by the Trustee referred to on the
reverse hereof by manual signature, this Note shall not be entitled to any
benefit of this Indenture or be valid or obligatory for any purpose.

 

	
  MARKWEST ENERGY FINANCE 

  	
   

  	
  MARKWEST ENERGY PARTNERS, L.P.

  
	
  CORPORATION

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MarkWest Energy GP, L.L.C.,

  
	
   

  	
   

  	
   

  	
  its General Partner

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By:

  	
   

  	
   

  	
  By:

  	
   

  
	
  Name:

  	
   

  	
   

  	
  Name:

  	
   

  
	
  Title

  	
   

  	
   

  	
  Title:

  	
   

  
								

 

	
  Certificate of Authentication:

  
	
   

  	
   

  
	
  This is one of the Notes referred to in the
  within-mentioned Indenture.

  
	
   

  	
   

  
	
  WELLS FARGO BANK, NATIONAL ASSOCIATION, as
  Trustee

  
	
  By: 

  	
   

  	
   

  
	
   

  	
  Authorized Signatory

  
	
   

  
	
  Date of Authentication:                                          ,             

  
					

 

(3) This is included in
Global Notes only.

 

3

 

[Back of Note]

 

83⁄4% [Series A] [Series B] Senior
Note due 2018

 

Capitalized terms used herein shall have the
meanings assigned to them in the Indenture referred to below unless otherwise
indicated.

1.             Interest.  MarkWest Energy Partners, L.P., a Delaware
limited partnership (the “Partnership”), and MarkWest Energy Finance
Corporation, a Delaware corporation (“MarkWest Finance” and, together with
the Partnership, the “Issuers”), promise to pay interest on the principal
amount of this Note at 83⁄4% per annum and shall pay any Additional Interest
payable pursuant to Section             of
the Registration Rights Agreement referred to below.  The Issuers will pay interest (including
Additional Interest, if any) semi-annually on April 15 and October 15
of each year, or if any such day is not a Business Day, on the next succeeding
Business Day (each an “Interest Payment Date”). 
Interest on the Notes will accrue from the most recent date to which
interest has been paid or, if no interest has been paid, from                      ,       ;
provided that if there is no existing Default in the payment of interest, and
if this Note is authenticated between a record date referred to on the face
hereof and the next succeeding Interest Payment Date, interest shall accrue
from such next succeeding Interest Payment Date; provided, further, that the
first Interest Payment Date shall be October 15, 2008.  The Issuers shall pay interest (including
post-petition interest in any proceeding under any Bankruptcy Law) on overdue
principal and premium, if any, from time to time on demand at the rate then in
effect; the Issuers shall pay interest (including post-petition interest in any
proceeding under any Bankruptcy Law) on overdue installments of interest
(including Additional Interest, if any), without regard to any applicable grace
periods, from time to time on demand at the same rate to the extent lawful.  Interest will be computed on the basis of a
360-day year comprised of twelve 30-day months.

 

2.             Method
of Payment.  The Issuers will pay
interest (including Additional Interest, if any) on the Notes (except defaulted
interest) to the Persons who are registered Holders of Notes at the close of
business on the April 1 or October 1  next
preceding the Interest Payment Date, even if such Notes are cancelled after
such record date and on or before such Interest Payment Date, except as
provided in Section 2.12 of the Indenture with respect to defaulted
interest.  The Notes will be payable as
to principal, premium and interest (including Additional Interest, if any) at
the office or agency of the Paying Agent maintained for such purpose in Dallas,
Texas, or, at the option of the Issuers, payment of interest (including
Additional Interest, if any) may be made by check mailed to the Holders at
their addresses set forth in the register of Holders, and provided that payment
by wire transfer of immediately available funds will be required with respect
to principal of, interest (including Additional Interest, if any) and premium
on, all Global Notes and all other Notes the Holders of which shall have
provided wire transfer instructions to the Issuers or the Paying Agent.  Such payment shall be in such coin or
currency of the United States of America as at the time of payment is legal
tender for payment of public and private debts.

 

3.             Paying
Agent and Registrar.  Initially, Wells
Fargo Bank, National Association, the Trustee under the Indenture, will act as
Paying Agent and Registrar.  The Issuers
may change

 

4

 

any Paying Agent or Registrar
without prior notice to any Holder.  The
Issuers or any of their Subsidiaries may act in any such capacity.

 

4.             Indenture.  The Issuers issued the Notes under an
Indenture dated as of April 15, 2008 (“Indenture”) among the Issuers,
the Subsidiary Guarantors and the Trustee. 
The terms of the Notes include those stated in the Indenture and those
made part of the Indenture by reference to the Trust Indenture Act of 1939, as
amended (15 U.S. Code Sections 77aaa-77bbbb). 
The Notes are subject to all such terms, and Holders are referred to the
Indenture and such Act for a statement of such terms.  To the extent any provision of this Note
conflicts with the express provisions of the Indenture, the provisions of the
Indenture shall govern and be controlling to the extent permitted by law.  The Notes are unsecured general obligations
of the Issuers.

 

5.             Optional
Redemption.  Subject to the additional
terms and conditions set forth in the Indenture:

 

(a)           On and after April 15, 2013, the
Issuers shall have the option to redeem the Notes, in whole or in part from
time to time, on at least 30 but not more than 60 days’ prior notice mailed to
the registered address of each Holder of Notes to be so redeemed, at the
redemption prices (expressed as percentages of principal amount) set forth
below, plus accrued and unpaid interest (including Additional Interest, if
any), if any, to the applicable redemption date (subject to the rights of
Holders of record on the relevant record date to receive interest due on an
Interest Payment Date that is on or prior to the redemption date), if redeemed
during the twelve-month period beginning on April 15 of the years
indicated below:

 

	
  YEAR

  	
   

  	
  PERCENTAGE

  	
   

  
	
  2013

  	
   

  	
  104.375

  	
  %

  
	
  2014

  	
   

  	
  102.917

  	
  %

  
	
  2015

  	
   

  	
  101.458

  	
  %

  
	
  2016 and thereafter

  	
   

  	
  100.000

  	
  %

  

 

(b)           Before April 15, 2013, the Issuers may
redeem all or, from time to time, a part of the Notes upon not less than 30 nor
more than 60 days’ notice, at a redemption price equal to:

 

(i)            100% of the aggregate
principal amount of the Notes to be redeemed, plus accrued and unpaid interest,
if any, to the applicable redemption date (subject to the right of Holders of
record on the relevant record date to receive interest due on an Interest
Payment Date that is on or prior to the redemption date), plus

 

(ii)           the Make Whole Amount.

 

(c)           Before April 15, 2011, the Issuers may
on any one or more occasions redeem in the aggregate up to 35% of the aggregate
principal amount of Notes issued under the Indenture with the net cash proceeds
of one or more Equity Offerings at a redemption price equal to 108.750% of the
principal amount of the Notes to be redeemed, plus accrued and unpaid interest,
if any, to the redemption date (subject to the right of Holders of record on a
record date to receive interest due on the relevant Interest Payment Date that
is on or prior to the redemption date); provided that

 

5

 

(i)            at least 65% of the
aggregate principal amount of Notes issued under the Indenture remains
outstanding after each such redemption; and

 

(ii)           any redemption occurs
within 60 days after the closing of such Equity Offering (without regard to any
over-allotment option).

 

6.             Mandatory
Redemption.  Except as set forth in
paragraph 7 below, the Issuers shall not be required to make mandatory
redemption payments with respect to the Notes.

 

7.             Repurchase
at Option of Holder.  Subject to the
additional terms and conditions set forth in the Indenture:

 

(a)           If there is a Change of Control, each Holder
of Notes will have the right to require the Issuers to repurchase all or any
part (equal to $2,000 or an integral multiple of $1,000 in excess thereof) of
such Holder’s Notes (the “Change of Control Offer”) at a purchase price equal
to 101% of the aggregate principal amount of the Notes repurchased plus accrued
and unpaid interest (including Additional Interest, if any) thereon, if any, to
the date of purchase.  Within 30 days
following any Change of Control, the Issuers shall mail a notice to each Holder
setting forth the procedures governing the Change of Control Offer as required
by the Indenture and information regarding such other matters as is required
under Section 4.06 of the Indenture. 
The Holder of this Note may elect to have this Note or a portion hereof
in an authorized denomination purchased by completing the form entitled “Option
of Holder to Elect Purchase” appearing below and tendering this Note pursuant
to the Change of Control Offer.

 

(b)           If the Issuers or any Restricted Subsidiary
of the Partnership consummates an Asset Sale, in certain circumstances
specified in Section 4.07 of the Indenture the Issuers shall commence a pro
rata offer to all Holders of Notes and all holders of other Indebtedness that
is pari passu in right of payment with the Notes containing provisions similar
to those set forth in the Indenture with respect to offers to purchase or
redeem with the proceeds of sales of assets (an “Asset Sale Offer”) pursuant to
Section 3.09 of the Indenture to purchase the maximum principal amount of
Notes and such other pari passu Indebtedness that may be purchased out of the
Excess Proceeds at an offer price in cash in an amount equal to 100% of the
principal amount thereof plus accrued and unpaid interest (including Additional
Interest, if any, in the case of the Notes) thereon, if any, to the date of
purchase in accordance with the procedures set forth in the Indenture.  If the aggregate principal amount of Notes
surrendered by Holders thereof exceeds the amount of Excess Proceeds allocated
for repurchase of Notes, the Trustee shall select the Notes to be purchased on
a pro rata basis.  Holders of Notes that
are the subject of an Asset Sale Offer will receive an offer to purchase from
the Issuers prior to any related purchase date and may elect to have such Notes
purchased by completing the form entitled “Option of Holder to Elect Purchase”
on the reverse of the Notes.

 

8.             Notice
of Redemption.  Notice of redemption will
be mailed at least 30 days but not more than 60 days before the redemption date
to each Holder whose Notes are to be redeemed at its registered address.  Notes in denominations larger than $2,000 may
be redeemed in part but only in whole multiples of $1,000, unless all of the
Notes held by a Holder are to be redeemed. 
On and after the redemption date interest (including Additional
Interest, if any)

 

6

 

ceases to accrue on Notes or portions thereof called for redemption
unless the Issuers defaults in making such redemption payment.

 

9.             Denominations,
Transfer, Exchange.  The Notes are in
registered form without coupons in minimum denominations of $2,000 or integral
multiples of $1,000 in excess thereof. 
The transfer of Notes may be registered and Notes may be exchanged as
provided in the Indenture.  The Registrar
and the Trustee may require a Holder, among other things, to furnish
appropriate endorsements and transfer documents and the Issuers may require a
Holder to pay any taxes and fees required by law or permitted by the
Indenture.  The Issuers need not exchange
or register the transfer of any Note or portion of a Note selected for
redemption, except for the portion of any Note being redeemed in part that is
not being redeemed.  Also, the Issuers
need not exchange or register the transfer of any Notes for a period of 15 days
before the mailing of a notice of redemption or during the period between a
record date and the corresponding Interest Payment Date.

 

10.           Persons
Deemed Owners.  The registered Holder of
a Note may be treated as its owner for all purposes.

 

11.           Amendment,
Supplement and Waiver.  Subject to
certain exceptions, the Indenture, the Guarantees or the Notes may be amended
or supplemented with the consent of the Holders of at least a majority in
aggregate principal amount of the then outstanding Notes, and any existing
default or compliance with any provision of the Indenture, the Guarantees or
the Notes may be waived with the consent of the Holders of a majority in
aggregate principal amount of the then outstanding Notes.  Without the consent of any Holder of a Note,
the Indenture, the Guarantees or the Notes may be amended or supplemented to cure
any ambiguity, defect or inconsistency, to provide for uncertificated Notes in
addition to or in place of certificated Notes, to provide for the assumption of
an Issuer’s or a Subsidiary Guarantor’s obligations to Holders of the Notes in
case of a merger or consolidation or sale of all or substantially all of such
Issuer’s assets, to add or release Subsidiary Guarantors pursuant to the terms
of the Indenture, to make any change that would provide any additional rights
or benefits to the Holders of the Notes or surrender any right or power
conferred upon the Issuers or the Subsidiary Guarantors by the Indenture that
does not adversely affect the rights under the Indenture of any such Holder, to
provide for the issuance of additional Notes in accordance with the limitations
set forth in the Indenture, to comply with the requirements of the SEC in order
to effect or maintain the qualification of the Indenture under the Trust
Indenture Act, to evidence or provide for the acceptance of appointment under
the Indenture of a successor Trustee, to add additional Events of Default or to
secure the Notes and/or the Guarantees.

 

12.           Defaults
and Remedies.  Events of Default include
in summary form: (i) default for 30 days in the payment when due of
interest on, including Additional Interest, if any, with respect to, the Notes;
(ii) default in payment when due of the principal of or premium, if any,
on the Notes; (iii) failure by the Partnership or any of its Restricted
Subsidiaries to comply with Section 5.01 of the Indenture; (iv) failure
by the Partnership to comply with the provisions described under Section 3.09,
4.06, 4.07, 4.08, 4.09, 4.10, 4.11. 4.12, 4.13, 4.14, 4.15, 4.16 or 4.17 of the
Indenture for 30 days or under Section 4.18 of the Indenture for 90 days,
in each case after notice to the Issuers by the Trustee or to the Issuers and
Trustee by Holders of at least 25% in aggregate principal amount of the Notes
then outstanding (provided that no such notice need

 

7

 

be given, and an Event of
Default shall occur, 30 days after a failure to comply with the covenants in Section 4.08
or 4.09 of the Indenture, unless theretofore cured), in each case other than a
failure to purchase Notes which will constitute an Event of Default under
clause (ii) above; (v) failure by the Partnership to comply with any
of its other agreements in the Indenture for 60 days after notice to the
Issuers by the Trustee or to the Issuers and Trustee by Holders of at least 25%
in aggregate principal amount of the Notes then outstanding; (vi) default
under any mortgage, indenture or instrument under which there may be issued or
by which there may be secured or evidenced any Indebtedness for money borrowed
by an Issuer or any Restricted Subsidiary of the Partnership (or the payment of
which is guaranteed by an Issuer or any Restricted Subsidiary of the
Partnership), whether such Indebtedness or guarantee now exists, or is created
after the date of the Indenture, if that default (a) is caused by a failure
to pay principal of or premium, if any, or interest on such Indebtedness prior
to the expiration of the grace period provided in such Indebtedness (a “Payment
Default”) or (b) results in the acceleration of such Indebtedness prior to
its express maturity and, in each case, the principal amount of any such
Indebtedness, together with the principal amount of any other such Indebtedness
under which there has been a Payment Default or the maturity of which has been
so accelerated, aggregates $20.0 million or more; provided that if any such
default is cured or waived or any such acceleration rescinded, or such
Indebtedness is repaid, within a period of 30 days from the continuation of
such default beyond the applicable grace period or the occurrence of such
acceleration, as the case may be, such Event of Default and any consequential
acceleration of the Notes shall be automatically rescinded, so long as such
rescission does not conflict with any judgment or decree; (vii) the
failure by an Issuer or any Restricted Subsidiary of the Partnership to pay
final judgments by courts of competent jurisdiction aggregating in excess of
$20.0 million, which judgments are not paid, discharged or stayed for a period
of 60 days; (viii) except as permitted by the Indenture, any Guarantee of
a Subsidiary Guarantor shall be held in any judicial proceeding to be
unenforceable or invalid or shall cease for any reason to be in full force and
effect or any Subsidiary Guarantor, or any Person acting on behalf of any
Subsidiary Guarantor, shall deny or disaffirm its obligations under its
Guarantee; and (ix) certain events of bankruptcy or insolvency with
respect to an Issuer or any Restricted Subsidiary of the Partnership that is a
Significant Subsidiary or any group of Restricted Subsidiaries that, taken as a
whole, would constitute a Significant Subsidiary.  If any Event of Default occurs and is
continuing, the Trustee may or at the request of the Holders of at least 25% in
aggregate principal amount of the then outstanding Notes shall declare all the
Notes to be due and payable. 
Notwithstanding the foregoing, in the case of an Event of Default
arising from certain events of bankruptcy or insolvency, with respect to an
Issuer, all outstanding Notes will become due and payable without further
action or notice.  Holders may not
enforce the Indenture or the Notes except as provided in the Indenture.  Subject to certain limitations, Holders of a
majority in aggregate principal amount of the then outstanding Notes may direct
the Trustee in its exercise of any trust or power.  The Trustee may withhold from Holders of the
Notes notice of any continuing Default or Event of Default (except a Default or
Event of Default relating to the payment of principal or interest) if it
determines that withholding notice is in their interest.

 

The Holders of a majority in aggregate
principal amount of the Notes then outstanding by notice to the Trustee may on
behalf of the Holders of all of the Notes waive any existing Default or Event
of Default and its consequences under the Indenture except a continuing Default
or Event of Default in the payment of interest (including Additional Interest,
if any) on, or the principal or premium, if any, of the Notes.  The Issuers and the Subsidiary Guarantors are

 

8

 

required to deliver to the
Trustee annually a statement regarding compliance with the Indenture, and the
Issuers are required upon becoming aware of any Default or Event of Default, to
deliver to the Trustee a statement specifying such Default or Event of Default.

 

13.           Trustee
Dealings with Partnership.  The Trustee,
in its commercial banking or any other capacity, may make loans to, accept
deposits from, and perform services for the Partnership or its Affiliates, and
may otherwise deal with the Partnership or its Affiliates, as if it were not
the Trustee.

 

14.           No personal liability of directors, officers,
employees and unitholders and no recourse against General Partner.  Neither the General Partner nor any
past, present or future director, officer, partner, employee, incorporator,
manager or unitholder or other owner of Equity Interests of the Issuers, the
General Partner or any Subsidiary Guarantor, as such, shall have any liability
for any Obligations of the Issuers or the Subsidiary Guarantors under the
Notes, the Indenture or the Guarantees or for any claim based on, in respect
of, or by reason of, such Obligations or their creation.  Each Holder by accepting a Note waives and
releases all such liability.  The waiver
and release are part of the consideration for issuance of the Notes.

 

15.           Authentication.  This Note shall not be valid until
authenticated by the manual signature of the Trustee or an authenticating
agent.

 

16.           Abbreviations.  Customary abbreviations may be used in the
name of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN
ENT (= tenants by the entireties), JT TEN (= joint tenants with right of
survivorship and not as tenants in common), CUST (= Custodian), and U/G/M/A (=
Uniform Gifts to Minors Act).

 

17.           Additional
Rights and Obligations of Holders of Restricted Global Notes and Restricted
Certificated Notes.  In addition to the
rights provided to Holders of Notes under the Indenture, Holders of Restricted
Global Notes and Restricted Certificated Notes shall have all the rights and
obligations set forth in the Registration Rights Agreement dated as of                   ,          ,
among the Issuers, the Subsidiary Guarantors and the parties named on the
signature pages thereof (the “Registration Rights Agreement”).

 

18.           CUSIP
Numbers.  Pursuant to a recommendation
promulgated by the Committee on Uniform Security Identification Procedures, the
Issuers have caused CUSIP numbers to be printed on the Notes and the Trustee
may use CUSIP numbers in notices of redemption as a convenience to
Holders.  No representation is made as to
the accuracy of such numbers either as printed on the Notes or as contained in
any notice of redemption and reliance may be placed only on the other identification
numbers placed thereon.  The Issuers will
furnish to any Holder upon written request and without charge a copy of the
Indenture and/or the Registration Rights Agreement.

 

9

 

	
   

  	
  Requests may
  be made to:

  
	
   

  
	
   

  	
  MarkWest
  Energy Partners, L.P.

  
	
   

  	
  1515 Arapahoe
  St., Tower II, Suite 700

  
	
   

  	
  Denver,
  Colorado 80202

  
	
   

  	
  Attention:
  Chief Financial Officer

  
			

 

10

 

[FORM OF ASSIGNMENT]

 

To assign this Note, fill in the form below: (I) or (we) assign and
transfer this Note to:

 

 

(Insert assignee’s soc. sec. or tax I.D. no.)

 

 

(Print or type name, address and zip code of
assignee)

 

and irrevocably appoint                                                                                             

to transfer this Note on the books of the
Issuers.  The agent may substitute
another to act for him.

 

	
  Date:

  	
   

  	
   

  	
   

  	
  Your Signature:

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
  (Sign exactly as name

  appears on the other side of

  this Note)

  

 

Signature
Guarantee*

 

*              NOTICE:
The Signature must be guaranteed by an Institution which is a member of one of
the following recognized signature Guarantee Programs:

 

(i) The Securities Transfer
Agent Medallion Program (STAMP); (ii) The New York Stock Exchange
Medallion Program (MNSP); (iii) The Stock Exchange Medallion Program
(SEMP); or (iv) in such other guarantee program acceptable to the Trustee.

 

11

 

OPTION OF HOLDER TO ELECT PURCHASE

 

If you want to elect to have this Note
purchased by the Issuers pursuant to Sections 3.09 and 4.07 or Section 4.06
of the Indenture, check the box below:

 

	
  o Sections 3.09 and 4.07

  	
   

  	
  o Section 4.06

  

 

If you want to elect to have only part of the
Note purchased by the Issuers pursuant to Sections 3.09 and 4.07 or Section 4.06
of the Indenture, state the amount you elect to have purchased (must be a
minimum of $2,000 or an integral multiple of $1,000 in excess thereof):

 

	
  $

  	
   

  	
   

  	
   

  
	
   

  	
   

  
	
  Date:

  	
   

  	
   

  	
  Your Signature:

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  
	
  Date:

  	
   

  	
   

  	
  Your Signature:

  	
   

  
	
   

  	
   

  	
   

  	
  (Sign exactly as name appears on the

  other side of this Note)

  
											

 

Signature Guarantee*

 

*              NOTICE:
The Signature must be guaranteed by an Institution which is a member of one of
the following recognized signature Guarantee Programs:

 

(i) The Securities Transfer
Agent Medallion Program (STAMP); (ii) The New York Stock Exchange
Medallion Program (MNSP); (iii) The Stock Exchange Medallion Program
(SEMP); or (iv) in such other guarantee program acceptable to the Trustee.

 

12

 

SCHEDULE OF EXCHANGES OF INTERESTS IN THE
GLOBAL NOTE*

 

The following exchanges of a part of this
Global Note for an interest in another Global Note or for a Certificated Note,
or exchanges of a part of another Global Note or Certificated Note for an
interest in this Global Note, have been made:

 

	
  Date of
  Exchange

  	
   

  	
  Signature of

  authorized signatory

  of Trustee or Note

  Custodian

  	
   

  	
  Amount of decrease

  in Principal amount

  of this Global Note

  	
   

  	
  Amount of increase

  in Principal amount

  of this Global Note

  	
   

  	
  Principal amount

  of this Global Note

  following such

  decrease or increase

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  

 

*              This
schedule should only be included if the Note is issued in global form.

 

13

 

EXHIBIT B

 

FORM OF CERTIFICATE OF TRANSFER

 

	
  Wells Fargo
  Bank, National Association

  
	
  1445 Ross
  Avenue – Second Floor

  
	
  Dallas, Texas
  75202-2812

  
	
  Attention:
  Corporate Trust Department

  

 

Re:          83⁄4%
Senior Notes due 2018 of MarkWest Energy Partners, L.P. and MarkWest Energy
Finance Corporation

 

Reference is hereby made to the
Indenture, dated as of April 15, 2008 (the “Indenture”), among MarkWest
Energy Partners, L.P. and MarkWest Energy Finance Corporation, as issuers (the “Issuers”),
the Persons acting as guarantors and named therein (the “Subsidiary Guarantors”)
and Wells Fargo Bank, National Association, as trustee.  Capitalized terms used but not defined herein
shall have the meanings given to them in the Indenture.

 

                                                                              ,
(the “Transferor”) owns and proposes to transfer the Note[s] or interest in
such Note[s] specified in Annex A hereto, in the principal amount of $                                        
in such Note[s] or interests (the “Transfer”), to                                         
(the “Transferee”), as further specified in Annex A hereto.  In connection with the Transfer, the
Transferor hereby certifies that:

 

[CHECK ALL THAT APPLY]

 

1. o
Check if Transferee will take delivery of a beneficial interest in the 144A
Global Note or a Certificated Note Pursuant to Rule 144A.  The Transfer is being effected pursuant to
and in accordance with Rule 144A under the United States Securities Act of
1933, as amended (the “Securities Act”), and, accordingly, the Transferor
hereby further certifies that the beneficial interest or Certificated Note is
being transferred to a Person that the Transferor reasonably believed and
believes is purchasing the beneficial interest or Certificated Note for its own
account, or for one or more accounts with respect to which such Person
exercises sole investment discretion, and such Person and each such account is
a “qualified institutional buyer” within the meaning of Rule 144A in a
transaction meeting the requirements of Rule 144A and such Transfer is in
compliance with any applicable blue sky securities laws of any state of the
United States.  Upon consummation of the
proposed Transfer in accordance with the terms of the Indenture, the
transferred beneficial interest or Certificated Note will be subject to the
restrictions on transfer enumerated in the Private Placement Legend printed on
the 144A Global Note and/or the Certificated Note and in the Indenture and the
Securities Act.

 

2. o
Check if Transferee will take delivery of a beneficial interest in the
Regulation S Global Note or a Certificated Note pursuant to Regulation S.  The Transfer is being effected pursuant to
and in accordance with Rule 903 or Rule 904 under the Securities Act
and, accordingly, the Transferor hereby further certifies that (i) the
Transfer is not being made to a person in the United States and (x) at the
time the buy order was originated, the Transferee was outside the United States
or such Transferor and any Person acting on its behalf reasonably

 

1

 

believed and believes that the
Transferee was outside the United States or (y) the transaction was
executed in, on or through the facilities of a designated offshore securities
market and neither such Transferor nor any Person acting on its behalf knows
that the transaction was prearranged with a buyer in the United States, (ii) no
directed selling efforts have been made in contravention of the requirements of
Rule 903(b) or Rule 904(b) of Regulation S under the Securities
Act, (iii) the transaction is not part of a plan or scheme to evade the
registration requirements of the Securities Act, and (iv) if the proposed
transfer is being made prior to the expiration of the Distribution Compliance
Period, the transfer is not being made to a U.S. Person or for the account or
benefit of a U.S. Person (other than an Initial Purchaser).  Upon consummation of the proposed transfer in
accordance with the terms of the Indenture, the transferred beneficial interest
or Certificated Note will be subject to the restrictions on Transfer enumerated
in the Private Placement Legend printed on the Regulation S Global Note and/or
the Certificated Note and in the Indenture and the Securities Act.

 

3. o
Check and complete if Transferee will take delivery of a beneficial interest in
the Restricted Global Note or a Certificated Note pursuant to any provision of
the Securities Act other than Rule 144A or Regulation S.  The Transfer is being effected in compliance
with the transfer restrictions applicable to beneficial interests in Restricted
Global Notes and Restricted Certificated Notes and pursuant to and in
accordance with the Securities Act and any applicable blue sky securities laws
of any state of the United States, and accordingly the Transferor hereby
further certifies that (check one):

 

(a) o
such Transfer is being effected pursuant to and in accordance with Rule 144
under the Securities Act; or

 

(b) o
such Transfer is being effected to the Partnership, MarkWest Finance or a
Subsidiary of the Partnership; or

 

(c) o
such Transfer is being effected to an Institutional Accredited Investor and
pursuant to an exemption from the registration requirements of the Securities
Act other than Rule 144A, Rule 144 or Rule 904, and the
Transferor hereby further certifies that the Transfer complies with the
transfer restrictions applicable to beneficial interests in a Restricted Global
Note or Restricted Certificated Notes and the requirements of the exemption
claimed, which certification is supported by (1) a certificate executed by
the Transferee in the form of Exhibit E to the Indenture and (2) an
Opinion of Counsel provided by the Transferor or the Transferee (a copy of
which the Transferor has attached to this certification), to the effect that
such Transfer is in compliance with the Securities Act.  Upon consummation of the proposed transfer in
accordance with the terms of the Indenture, the transferred beneficial interest
or Certificated Note will be subject to the restrictions on transfer enumerated
in the Private Placement Legend printed on the Restricted Global Note and/or
the Certificated Notes and in the Indenture and the Securities Act.

 

4. o
Check if Transferee will take delivery of a beneficial interest in an
Unrestricted Global Note or of an Unrestricted Certificated Note.

 

(a) o
Check if Transfer is pursuant to Rule 144. 
(i) The Transfer is being effected pursuant to and in accordance
with Rule 144 under the Securities Act and in compliance with the transfer
restrictions contained in the Indenture and any applicable blue sky securities
laws of any

 

2

 

state of the United States and (ii) the
restrictions on transfer contained in the Indenture and the Private Placement
Legend are not required in order to maintain compliance with the Securities
Act.  Upon consummation of the proposed
Transfer in accordance with the terms of the Indenture, the transferred
beneficial interest or Certificated Note will no longer be subject to the
restrictions on transfer enumerated in the Private Placement Legend printed on
the Restricted Global Notes, on Restricted Certificated Notes and in the
Indenture.

 

(b) o
Check if Transfer is Pursuant to Regulation S. 
(i) The Transfer is being effected pursuant to and in accordance with
Rule 903 or Rule 904 under the Securities Act and in compliance with
the transfer restrictions contained in the Indenture and any applicable blue
sky securities laws of any state of the United States and (ii) the
restrictions on transfer contained in the Indenture and the Private Placement
Legend are not required in order to maintain compliance with the Securities
Act.  Upon consummation of the proposed
Transfer in accordance with the terms of the Indenture, the transferred
beneficial interest or Certificated Note will no longer be subject to the
restrictions on transfer enumerated in the Private Placement Legend printed on
the Restricted Global Notes, on Restricted Certificated Notes and in the
Indenture.

 

(c) o
Check if Transfer is Pursuant to Other Exemption.  (i) The Transfer is being effected
pursuant to and in compliance with an exemption from the registration
requirements of the Securities Act other than Rule 144, Rule 903 or Rule 904
and in compliance with the transfer restrictions contained in the Indenture and
any applicable blue sky securities laws of any state of the United States and (ii) the
restrictions on transfer contained in the Indenture and the Private Placement
Legend are not required in order to maintain compliance with the Securities
Act.  Upon consummation of the proposed
Transfer in accordance with the terms of the Indenture, the transferred
beneficial interest or Certificated Note will not be subject to the
restrictions on transfer enumerated in the Private Placement Legend printed on
the Restricted Global Notes or Restricted Certificated Notes and in the
Indenture.

 

(d) o
Check if Transfer is Pursuant to an Effective Registration Statement.  The transfer is being effected pursuant to an
effective registration statement under the Securities Act and in compliance
with the prospectus delivery requirements of the Securities Act.  Upon consummation of the proposed Transfer in
accordance with the terms of the Indenture, the transferred beneficial interest
or Certificated Note will not be subject to the restrictions on transfer
enumerated in the Private Placement Legend printed on the Restricted Global
Notes or Restricted Certificated Notes and in the Indenture.

 

This certificate and the statements contained
herein are made for your benefit and for the benefit of the Issuers, the
Subsidiary Guarantors and J.P. Morgan Securities Inc., RBC Capital Markets
Corporation, Wachovia Capital Markets, LLC, Banc of America Securities LLC,
Credit Suisse Securities (USA) LLC, Deutsche Bank Securities Inc., Fortis
Securities LLC and SunTrust Capital Markets, Inc. (collectively, the “Initial
Purchasers”), the Initial Purchasers of such Notes being transferred.  We acknowledge that you, the Issuers, the
Subsidiary Guarantors and the Initial Purchasers will rely upon our
confirmations, acknowledgments and agreements set forth herein, and we agree to
notify you promptly in writing if any of our representations or warranties
herein ceases to be accurate and complete.

 

3

 

	
  [Insert Name
  of Transferor]

  
	
   

  
	
  By:

  	
   

  	
   

  
	
  Name:

  	
   

  	
   

  
	
  Title:

  	
   

  	
   

  
	
   

  
	
  Dated:                      ,          

  
	
   

  
	
   

  
	
  cc: Issuers

  
	
   

  
	
  Initial Purchasers

  
					

 

4

 

ANNEX A TO CERTIFICATE OF TRANSFER

 

1.             The
Transferor owns and proposes to transfer the following:

 

[CHECK ONE OF (a) OR (b)]

 

(a) o
a beneficial interest in the:

 

(i) o
144A Global Note (CUSIP              ),
or

 

(ii) o
Regulation S Global Note (CUSIP              ),
or

 

(iii) o
IAI Global Note (CUSIP              );
or

 

(b) o
a Restricted Certificated Note.

 

2.             After
the Transfer the Transferee will hold:

 

[CHECK ONE]

 

(a) o
a beneficial interest in the:

 

(i) o
144A Global Note (CUSIP              ),
or

 

(ii) o
Regulation S Global Note (CUSIP              ),
or

 

(iii) o
IAI Global Note (CUSIP              ),
or

 

(iv) o
Unrestricted Global Note (CUSIP              );
or

 

(b) o
a Restricted Certificated Note; or

 

(c) o
an Unrestricted Certificated Note, in accordance with the terms of the
Indenture.

 

5

 

EXHIBIT C

 

FORM OF CERTIFICATE OF EXCHANGE

 

Wells Fargo Bank, National
Association

1445 Ross Avenue – Second Floor

Dallas, Texas  75202-2812

Attention: 
Corporate Trust Department

 

Re:                               83⁄4%
Senior Notes due 2018 of MarkWest Energy Partners, L.P. and MarkWest Energy
Finance Corporation

 

(CUSIP                     )

 

Reference is hereby made to the
Indenture, dated as of April 15, 2008 (the “Indenture”), among MarkWest
Energy Partners, L.P. and MarkWest Energy Finance Corporation, as issuers (the “Issuers”),
the Persons acting as guarantors and named therein (the “Subsidiary Guarantors”)
and Wells Fargo Bank, National Association, as trustee.  Capitalized terms used but not defined herein
shall have the meanings given to them in the Indenture.

 

                                               
(the “Owner”) owns and proposes to exchange the Note[s] or interest in such
Note[s] specified herein, in the principal amount of $                                          
in such Note[s] or interests (the “Exchange”). 
In connection with the Exchange, the Owner hereby certifies that:

 

1.             Exchange of Restricted Certificated Notes or Beneficial
Interests in a Restricted Global Note for Unrestricted Certificated Notes or
Beneficial Interests in an Unrestricted Global Note

 

(a)           [  ]           Check
if Exchange is from beneficial interest in a Restricted Global Note to
beneficial interest in an Unrestricted Global Note.  In connection with the Exchange of the Owner’s
beneficial interest in a Restricted Global Note for a beneficial interest in an
Unrestricted Global Note in an equal principal amount, the Owner hereby
certifies (i) the beneficial interest is being acquired for the Owner’s
own account without transfer, (ii) such Exchange has been effected in
compliance with the transfer restrictions applicable to the Global Notes and
pursuant to and in accordance with the United States Securities Act of 1933, as
amended (the “Securities Act”), (iii) the restrictions on transfer
contained in the Indenture and the Private Placement Legend are not required in
order to maintain compliance with the Securities Act and (iv) the
beneficial interest in an Unrestricted Global Note is being acquired in
compliance with any applicable blue sky securities laws of any state of the
United States.

 

(b)           [  ]           Check
if Exchange is from Restricted Certificated Note to Unrestricted Certificated
Note.  In connection with the Owner’s
Exchange of a Restricted Certificated Note for an Unrestricted Certificated
Note, the Owner hereby certifies (i) the Unrestricted Certificated Note is
being acquired for the Owner’s own account without transfer, (ii) such
Exchange has been effected in compliance with the transfer restrictions
applicable to Restricted Certificated Notes and pursuant to and in accordance
with the Securities Act, (iii) the restrictions on transfer contained in
the Indenture and the Private Placement Legend are not required in order to 

 

1

 

maintain compliance with the Securities Act
and (iv) the Unrestricted Certificated Note is being acquired in
compliance with any applicable blue sky securities laws of any state of the
United States.

 

This certificate and the
statements contained herein are made for your benefit and the benefit of the
Issuers, the Subsidiary Guarantors and J.P. Morgan Securities Inc., RBC Capital
Markets Corporation, Wachovia Capital Markets, LLC, Banc of America Securities
LLC, Credit Suisse Securities (USA) LLC, Deutsche Bank Securities Inc., Fortis
Securities LLC and SunTrust Capital Markets, Inc. (collectively, the “Initial
Purchasers”), the Initial Purchasers of such Notes being transferred.  We acknowledge that you, the Issuers, the
Subsidiary Guarantors and the Initial Purchasers will rely upon our
confirmations, acknowledgments and agreements set forth herein, and we agree to
notify you promptly in writing if any of our representations or warranties
herein ceases to be accurate and complete.

 

[Insert Name of Owner]

 

	
  By:

  	
   

  	
   

  
	
  Name:

  	
   

  	
   

  
	
  Title:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Dated: 

  	
   

  	
  ,

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  cc:

  	
  Issuers

  	
   

  
	
  Initial Purchasers

  	
   

  
							

 

2

 

EXHIBIT D

 

FORM OF GUARANTEE NOTATION

 

Subject to the limitations set
forth in the Indenture (the “Indenture”) referred to in the Note upon which
this notation is endorsed, each of the entities listed on Schedule A thereto
(hereinafter referred to as the “Subsidiary Guarantors,” which term includes
any successor or additional Subsidiary Guarantor under the Indenture) (i) has
unconditionally guaranteed: (a) the due and punctual payment of the
principal of, premium and interest (including Additional Interest, if any) on
the Notes, whether at maturity or interest payment date, by acceleration, call
for redemption or otherwise, (b) the due and punctual payment of interest
on the overdue principal of, premium and interest (including Additional
Interest, if any) if lawful, on the Notes, (c) the due and punctual
payment or performance of all other Obligations of the Issuers to the Holders
or the Trustee, all in accordance with the terms set forth in the Indenture,
and (d) in case of any extension of time of payment or renewal of any
Notes or any of such other Obligations, the prompt payment in full thereof when
due or performance thereof in accordance with the terms of the extension or
renewal, whether at Stated Maturity, by acceleration or otherwise and (ii) has
agreed to pay any and all costs and expenses (including reasonable attorneys’
fees) incurred by the Trustee or any Holder in enforcing any rights under this
Guarantee.

 

This Guarantee Notation is
subject to the limitations set forth in the Indenture, including Article 10
thereof.

 

No member, manager, stockholder,
partner, officer, employee, director or incorporator, as such, past, present or
future, of the Subsidiary Guarantors shall have any personal liability under
this Guarantee by reason of his or its status as such member, manager, partner,
stockholder, officer, employee, director or incorporator.

 

The Guarantee shall be binding
upon each Subsidiary Guarantor and its successors and assigns and shall inure
to the benefit of the successors and assigns of the Trustee and the Holders
and, in the event of any transfer or assignment of rights by any Holder or the
Trustee, the rights and privileges herein conferred upon that party shall
automatically extend to and be vested in such transferee or assignee, all
subject to the terms and conditions hereof.

 

Each Guarantee shall not be
valid or obligatory for any purpose until the certificate of authentication on
the Note upon which this notation of Guarantee is noted shall have been
executed by the Trustee under the Indenture by the manual signature of one of
its authorized officers.

 

The Subsidiary Guarantors may be
released from their Guarantees upon the terms and subject to the conditions
provided in the Indenture.

 

3

 

Subsidiary Guarantors:

 

	
   

  	
  MARKWEST HYDROCARBON, INC.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST ENERGY GP, L.L.C.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MASON PIPELINE LIMITED LIABILITY COMPANY

  
	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  MARKWEST HYDROCARBON, INC.

  
	
   

  	
   

  	
  its Sole Member

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  

 

4

 

	
   

  	
  BASIN PIPELINE 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST ENERGY APPALACHIA, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST ENERGY EAST TEXAS GAS

  
	
   

  	
  COMPANY, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  

 

5

 

	
   

  	
  MARKWEST BLACKHAWK, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST GAS SERVICES, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST JAVELINA COMPANY, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  

 

6

 

	
   

  	
  MARKWEST JAVELINA PIPELINE COMPANY, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST LIBERTY GAS GATHERING, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST MICHIGAN PIPELINE 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  

 

7

 

	
   

  	
  MARKWEST NEW MEXICO, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST PINNACLE, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST PIONEER, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  

 

8

 

	
   

  	
  MARKWEST PIPELINE COMPANY, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST POWER TEX, 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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  

 

9

 

	
   

  	
  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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
					

 

10

 

	
   

  	
  MATREX, L.L.C.

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  Basin Pipeline L.L.C.

  
	
   

  	
   

  	
   

  	
  its Sole Member and Manager

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  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:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  

 

11

 

EXHIBIT E

 

FORM OF CERTIFICATE FROM

ACQUIRING INSTITUTIONAL ACCREDITED INVESTOR

 

MarkWest Energy Partners, L.P.

MarkWest Energy Finance Corporation

155 Inverness Drive West, Suite 200

Englewood, Colorado 80112

 

Wells Fargo Bank, National
Association

1445 Ross Avenue – Second Floor

Dallas, Texas  75202-2812

Attention: 
Corporate Trust Department

 

Re:                               83⁄4%
Senior Notes due 2018  issued by
MarkWest Energy Partners, L.P. and MarkWest Energy Finance Corporation

 

Reference is hereby made to the
Indenture, dated as of April 15, 2008 (the “Indenture”), among MarkWest
Energy Partners, L.P. (the “Partnership”) and MarkWest Energy Finance
Corporation  (“MarkWest Finance”), as issuers
(the “Issuers”), the Subsidiaries named therein, as Subsidiary Guarantors, and
Wells Fargo Bank, National Association, as trustee.  Capitalized terms used but not defined herein
shall have the meanings given to them in the Indenture.

 

In connection
with our proposed purchase of $                               
aggregate principal amount of:

 

(a) [  ] a beneficial interest in a Global Note, or

 

(b) [  ] a Certificated Note,

 

we confirm that:

 

1.             We understand that any subsequent transfer of the Series A
Notes or any interest therein is subject to certain restrictions and conditions
set forth in the Indenture and the undersigned agrees to be bound by, and not
to resell, pledge or otherwise transfer the Series A Notes or any interest
therein except in compliance with, such restrictions and conditions and the
United States Securities Act of 1933, as amended (the “Securities Act”).

 

2.             We understand that the offer and sale of the Series A
Notes have not been registered under the Securities Act, and that the Series A
Notes and any interest therein may not be offered or sold except as permitted
in the following sentence.  We agree, on
our own behalf and on behalf of any accounts for which we are acting as
hereinafter stated, that if we should sell the Series A Notes or any
interest therein, we will do so only (A) to the Partnership, MarkWest
Finance, or any subsidiary of the Partnership, (B) in the United States to
a person who the seller reasonably believes is a “qualified institutional buyer”
(as defined in Rule 144A under the Securities Act) in a transaction
meeting the requirements of Rule 144A, (C) outside the United States
in an offshore transaction in accordance with Rule 904 under the
Securities Act, (D)

 

1

 

pursuant to an exemption from registration
under the Securities Act provided by Rule 144 thereunder (if available), (E) to
an institutional “accredited investor” within the meaning of Rule 501(A)(1),
(2), (3) or (7) under the Securities Act that is an institutional
accredited investor acquiring the security for its own account or for the
account of such institutional accredited investor, in each case in a minimum
principal amount of the securities of $250,000, for investment purposes and not
with a view to or for offer or sale in connection with any distribution in
violation of the Securities Act or (F) pursuant to an effective
registration statement under the Securities Act, in each of cases (A) through
(E) in accordance with any applicable securities laws of any state of the
United States, and we further agree to provide to any person purchasing a
Certificated Note or beneficial interest in a Global Note from us in a transaction
meeting the requirements of clauses (B) through (E) of this paragraph
a notice advising such purchaser that resales thereof are restricted as stated
herein.

 

3.             We understand that, on any proposed resale of the Series A
Notes or beneficial interest therein, we will be required to furnish to you
such certifications, legal opinions and other information as you may reasonably
requires to confirm that the proposed sale complies with the foregoing
restrictions.  We further understand that
the Series A Notes purchased by us will bear a legend to the foregoing
effect.

 

4.             We are an institutional “accredited investor” (as defined
in Rule 501(a)(1), (2), (3) or (7) of Regulation D under the
Securities Act) and have such knowledge and experience in financial and
business matters as to be capable of evaluating the merits and risks of our
investment in the Series A Notes, and we and any accounts for which we are
acting are each able to bear the economic risk of our or its investment.  We are acquiring the Series A Notes for
investment purposes and not with a view to, or for offer or sale in connection
with, any distribution in violation of the Securities Act.

 

5.             We are acquiring the Series A Notes or beneficial
interest therein purchased by us for our own account or for one or more
accounts (each of which is an institutional “accredited investor”) as to each
of which we exercise sole investment discretion.

 

You are entitled to rely upon
this letter and are irrevocably authorized to produce this letter or a copy
hereof to any interested party in any administrative or legal proceedings or
official inquiry with respect to the matters covered hereby.

 

	
   

  	
   

  
	
   

  	
  [Insert Name of Institutional Accredited
  Investor]

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  
	
   

  	
  Title:

  
	
   

  
	
  Dated:

  	
   

  	
  ,

  	
   

  	
   

  	
   

  
								

 

2

 

ANNEX A

 

 

MARKWEST ENERGY PARTNERS, L.P.

 

MARKWEST ENERGY FINANCE CORPORATION

 

and

 

the Subsidiary Guarantors named herein

 

 

83⁄4% SENIOR NOTES DUE 2018

 

 

FORM OF SUPPLEMENTAL INDENTURE

 

DATED AS OF            
     ,       

 

 

WELLS FARGO BANK, NATIONAL ASSOCIATION,

 

Trustee

 

 

 

A-1

 

This SUPPLEMENTAL INDENTURE,
dated as of
                 
       ,        
is among MarkWest Energy Partners, L.P., a Delaware limited partnership (the “Partnership”),
MarkWest Energy Finance Corporation, a Delaware corporation (“MarkWest Finance”
and, together with the Partnership, the “Issuers”), each of the parties
identified under the caption “Subsidiary Guarantors” on the signature page hereto
(the “Subsidiary Guarantors”) and Wells Fargo Bank, National Association, a
national banking association, as Trustee.

 

RECITALS

 

WHEREAS, the Issuers, the
initial Subsidiary Guarantors and the Trustee entered into an Indenture, dated
as of April 15, 2008 (the “Indenture”), pursuant to which the Issuers have
issued $                          
in principal amount of 83⁄4% Senior Notes due 2018 (the “Notes”);

 

WHEREAS, Section 9.01(d) of
the Indenture provides that the Issuers, the Subsidiary Guarantors and the
Trustee may amend or supplement the Indenture in order to add Subsidiary
Guarantors pursuant to Section 4.13 or 5.01(c) thereof, without the
consent of the Holders of the Notes; and

 

WHEREAS, all acts and things
prescribed by the Indenture, by law and by the Certificate of Incorporation and
the Bylaws (or comparable constituent documents) of the Issuers, of the
Subsidiary Guarantors and of the Trustee necessary to make this Supplemental
Indenture a valid instrument legally binding on the Issuers, the Subsidiary
Guarantors and the Trustee, in accordance with its terms, have been duly done
and performed;

 

NOW, THEREFORE, to comply with
the provisions of the Indenture and in consideration of the above premises, the
Issuers, the Subsidiary Guarantors and the Trustee covenant and agree for the
equal and proportionate benefit of the respective Holders of the Notes as
follows:

 

ARTICLE 1

 

Section 1.01.          This Supplemental Indenture is
supplemental to the Indenture and does and shall be deemed to form a part of,
and shall be construed in connection with and as part of, the Indenture for any
and all purposes.

 

Section 1.02.          This Supplemental Indenture shall
become effective immediately upon its execution and delivery by each of the
Issuers, the Subsidiary Guarantors and the Trustee.

 

ARTICLE 2

 

From this date, in accordance
with Section 4.13 or 5.01(c) and by executing this Supplemental
Indenture, the Guarantors whose signatures appear below are subject to the
provisions of the Indenture to the extent provided for in Article 10
thereunder.

 

ARTICLE 3

 

Section 3.01.          Except as specifically modified
herein, the Indenture and the Notes are in all respects ratified and confirmed (mutatis mutandis) and shall remain in
full force and effect in

 

A-2

 

accordance with their terms
with all capitalized terms used herein without definition having the same
respective meanings ascribed to them as in the Indenture.

 

Section 3.02.          Except as otherwise expressly provided
herein, no duties, responsibilities or liabilities are assumed, or shall be
construed to be assumed, by the Trustee by reason of this Supplemental
Indenture.  This Supplemental Indenture
is executed and accepted by the Trustee subject to all the terms and conditions
set forth in the Indenture with the same force and effect as if those terms and
conditions were repeated at length herein and made applicable to the Trustee
with respect hereto.

 

Section 3.03.          THIS SUPPLEMENTAL INDENTURE SHALL BE
GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW
YORK.

 

 

Section 3.04.          The parties may sign any number of
copies of this Supplemental Indenture. 
Each signed copy shall be an original, but all of such executed copies
together shall represent the same agreement.

 

[NEXT PAGE IS SIGNATURE PAGE]

 

A-3

 

IN
WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to
be duly executed, all as of the date first written above.

 

	
   

  	
  MARKWEST
  ENERGY PARTNERS, L.P.

  
	
   

  	
   

  
	
   

  	
  BY:

  	
  MARKWEST
  ENERGY GP, L.L.C.,

  
	
   

  	
   

  	
  ITS GENERAL
  PARTNER

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By

  	
   

  
	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  MARKWEST
  ENERGY FINANCE CORPORATION

  
	
   

  	
   

  
	
   

  	
  By:

  	
   

  
	
   

  	
  Name:

  	
   

  
	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  SUBSIDIARY
  GUARANTORS

  
	
   

  	
   

  
	
   

  	
  [                                                                           ]

  
	
   

  	
   

  
	
   

  	
  By

  	
   

  
	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
  Title:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  WELLS FARGO BANK, NATIONAL ASSOCIATION,

  
	
   

  	
  as Trustee

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  By

  	
   

  
	
   

  	
   

  	
  Name:

  	
   

  
	
   

  	
   

  	
  Title:

  	
   

  
												

 

A-4

 

REGISTRATION RIGHTS
AGREEMENT

 

1Exhibit 4.2

 

April 15,
2008

 

REGISTRATION RIGHTS AGREEMENT

 

This REGISTRATION RIGHTS
AGREEMENT dated April 15, 2008 (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, Banc of America Securities LLC, Credit Suisse Securities (USA) LLC,
Deutsche Bank Securities Inc., Fortis Securities LLC and SunTrust Robinson
Humphrey, Inc. (collectively, the “Initial Purchasers”).

 

The Issuers, the
Guarantors and the Initial Purchasers are parties to that certain Purchase
Agreement dated April 10, 2008 (the “Purchase Agreement”), which
provides for the sale by the Issuers to the Initial Purchasers of $400,000,000
aggregate principal amount of the Issuers’ 8.75% Senior Notes due 2018 (the “Securities”)
which will be guaranteed on an unsecured senior basis by each of the
Guarantors.  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.

 

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

 

1

 

“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
mean the Indenture relating to the Securities dated as of April 15, 2008
among the Issuers, the Guarantors and Wells Fargo Bank, National Association,
as trustee, and as the same may be amended from time to time in accordance with
the terms thereof.

 

“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.

 

2

 

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

 

3

 

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 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 

 

4

 

post-effective
amendments, in each case including the Prospectus contained therein, all
exhibits thereto and any document incorporated by reference therein.

 

“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, 

 

5

 

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 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.

 

6

 

(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 October 15, 2008
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.

 

7

 

(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 October 15, 2008
(the “Target Registration Date”), the interest rate on the Registrable
Securities will be increased by (i) 0.25% 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 August 15, 2008, then the Target
Registration Date shall be extended by the number of days from and including August 15,
2008 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 

 

8

 

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 

 

9

 

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, 

 

10

 

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 

 

11

 

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 PARTNERS, L.P.

  	
   

  
	
   

  	
   

  
	
  By:

  	
  MARKWEST
  ENERGY GP, L.L.C.,

  	
   

  
	
   

  	
   its general partner

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By:

  	
  /s/
  Andrew L. Schroeder

  	
   

  
	
   

  	
  Name:
  Andrew L. Schroeder

  	
   

  
	
   

  	
  Title:
  Vice
  President Finance, Treasurer and Assistant Secretary

  
	
   

  	
   

  	
   

  
	
   

  	
   

  
	
  MARKWEST ENERGY FINANCE CORPORATION

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:

  	
  /s/
  Andrew L. Schroeder

  	
   

  
	
  Name:
  Andrew L. Schroeder

  	
   

  
	
  Title:
  Vice
  President Finance, Treasurer and Assistant Secretary

  	
   

  
					

 

20

 

 

	
   

  	
   

  	
  Guarantors:

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST HYDROCARBON,
  INC.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST ENERGY GP,
  L.L.C.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MASON PIPELINE LIMITED
  LIABILITY COMPANY

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MARKWEST HYDROCARBON,
  INC.,

  
	
   

  	
   

  	
   

  	
   

  	
  its Sole Member

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
						

 

21

	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  BASIN PIPELINE 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST ENERGY
  APPALACHIA, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST ENERGY
  EAST TEXAS GAS 

  COMPANY, 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/ Andrew L.
  Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

22

 

	
   

  	
   

  	
  MARKWEST BLACKHAWK,
  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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST GAS
  SERVICES, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  JAVELINA COMPANY, 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/ Andrew L.
  Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

23

 

	
   

  	
   

  	
  MARKWEST
  JAVELINA PIPELINE COMPANY, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST LIBERTY
  GAS GATHERING, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  MICHIGAN PIPELINE 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/ Andrew L.
  Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

24

 

	
   

  	
   

  	
  MARKWEST NEW
  MEXICO, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  PINNACLE, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST
  PIONEER, 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/ Andrew L.
  Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

25

 

	
   

  	
   

  	
  MARKWEST
  PIPELINE COMPANY, 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST 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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and Assistant
  Secretary

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  MARKWEST POWER
  TEX, 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/ Andrew L.
  Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

26

 

	
   

  	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  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/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  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/ Andrew L.
  Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

27

 

	
   

  	
   

  	
  MATREX, L.L.C.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  Basin Pipeline
  L.L.C.,

  
	
   

  	
   

  	
   

  	
   

  	
  its Sole Member
  and Manager

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

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

  
	
   

  	
   

  	
   

  	
   

  	
  its Managing
  Member

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By:

  	
  MARKWEST ENERGY
  PARTNERS, L.P.,

  
	
   

  	
   

  	
   

  	
   

  	
  its Managing
  Member

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By:

  	
  /s/ Andrew L. Schroeder

  
	
   

  	
   

  	
  Name:

  	
  Andrew
  L. Schroeder

  
	
   

  	
   

  	
  Title:

  	
  Vice President Finance, Treasurer and
  Assistant Secretary

  

 

28

 

Confirmed and accepted as
of the date first above written:

 

J.P.
MORGAN SECURITIES INC.

RBC
CAPITAL MARKETS CORPORATION

WACHOVIA
CAPITAL MARKETS, LLC

BANC
OF AMERICA SECURITIES LLC

CREDIT
SUISSE SECURITIES (USA) LLC

DEUTSCHE
BANK SECURITIES INC.

FORTIS
SECURITIES LLC

SUNTRUST
ROBINSON HUMPHREY, INC.

 

	
  By:
  J.P. MORGAN
  SECURITIES INC.

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:

  	
  /s/
  Adam Bernard

  	
   

  
	
  Name:
  Adam Bernard

  	
   

  
	
  Title:
  Executive Director

  	
   

  
			

 

29

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