0001104659-08-014750 Sample Contracts

Agreement of Joint Filing

Agreement of Joint Filing • March 3rd, 2008 • Markwest Energy Partners L P • Crude petroleum & natural gas

• Contract Type
  Agreement of Joint Filing
• Filed
  March 3rd, 2008
• Company
  Markwest Energy Partners L P
• Industry
  Crude petroleum & natural gas

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned parties hereby agree that the preceding Schedule 13D is being filed on behalf of each of them.

AMENDMENT NO. 4 TO AMENDED AND RESTATED CLASS B MEMBERSHIP INTEREST CONTRIBUTION AGREEMENT

Class B Membership Interest Contribution Agreement • March 3rd, 2008 • Markwest Energy Partners L P • Crude petroleum & natural gas

• Contract Type
  Class B Membership Interest Contribution Agreement
• Filed
  March 3rd, 2008
• Company
  Markwest Energy Partners L P
• Industry
  Crude petroleum & natural gas

This Amendment No. 4 to the Amended and Restated Class B Membership Interest Contribution Agreement dated as of October 26, 2007 (this “Amendment No. 4”) is dated effective February 19, 2008, and is by and between MarkWest Energy Partners, L.P. (“Buyer”), Frank M. Semple (“Semple”), John M. Fox (“Fox”), John C. Mollenkopf (“Mollenkopf”), Randy S. Nickerson (“Nickerson”), Kevin Kubat (“Kubat”), Jan Kindrick (“Kindrick”), and Nancy K. Buese (“Buese”).