QuickLinks -- Click here to rapidly navigate through this document
Form of Proxy for Holders of MarkWest Hydrocarbon, Inc. Common Stock
MARKWEST HYDROCARBON, INC. 1515 ARAPAHOE STREET TOWER 2, SUITE 700 DENVER, COLORADO 80202 | SUBMIT YOUR PROXY BY INTERNET—www.proxyvote.com Use the Internet to transmit your voting instructions and for electronic delivery of information up until 11:59 p.m. Eastern Time the day before the meeting date. Have your proxy card in hand when you access the web site and follow the instructions on your screen to obtain your records and to create an electronic voting instruction form. You will incur only your normal internet charges. | |
SUBMIT YOUR PROXY BY TELEPHONE—1-866-783-6390 | ||
Use any touch-tone telephone to transmit your voting instructions toll-free up until 11:59 p.m. Eastern Time the day before the meeting date. Have your proxy card in hand when you call and then follow the prerecorded instructions. | ||
SUBMIT YOUR PROXY BY MAIL | ||
Mark, sign and date your proxy card and return it in the enclosed postage-paid envelope toMarkWest Hydrocarbon, Inc. c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. Your proxy card must be received by the day before the meeting date to be counted in the final tabulation. |
TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS: | KEEP THIS PORTION FOR YOUR RECORDS | |
DETACH AND RETURN THIS PORTION ONLY |
THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED.
MarkWest Hydrocarbon, Inc.
Vote on Proposal | For | Against | Abstain | |||||
1. Approval and adoption of the Certificate of Amendment of the Certificate of Incorporation of MarkWest Hydrocarbon, Inc. (the "Corporation"). | o | o | o | |||||
2. Approval and adoption of the Agreement and Plan of Redemption and Merger by and among MarkWest Energy Partners, L.P. (the "Partnership"), MWEP, L.L.C. (the "Merger Sub") and the Corporation, dated as of September 5, 2007, as such agreement may be amended from time to time, pursuant to which the redemption will occur and the Merger Sub will merge with and into the Corporation with the Corporation surviving as a direct, wholly owned subsidiary of the Partnership. | o | o | o | |||||
3. Approval of the adjournment or postponement of the Special Meeting of Stockholders, if necessary or appropriate, to solicit additional proxies if there are insufficient votes at the time of the meeting to approve any of the foregoing proposals. | o | o | o |
This Proxy is revocable and, when properly executed, will be voted in the manner directed herein by the undersigned stockholder. If no direction is made, this Proxy will be voted FOR all of the above items.
Please sign exactly as your name appears hereon. Jointly owned shares will be voted as directed if one owner signs unless another owner instructs the contrary, in which case the shares will not be voted. If signing in a representative capacity, please indicate title and authority.
Signature [PLEASE SIGN WITHIN BOX] | Date | Signature (Joint Owners) | Date |
THE BOARD OF DIRECTORS OF THE CORPORATION RECOMMENDS A VOTE IN FAVOR OF ALL PROPOSALS
IF YOU HAVE ANY QUESTIONS OR NEED ASSISTANCE, PLEASE CALL THE CORPORATION AT (303) 925-9200.
THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS | ||
PROXY |
MARKWEST HYDROCARBON, INC.
1515 Arapahoe Street
Tower 2, Suite 700
Denver, Colorado 80202
The undersigned stockholder(s) of MarkWest Hydrocarbon, Inc. (the "Corporation"), having duly received the Notice of Special Meeting and Joint Proxy Statement/Prospectus dated January 7, 2008, hereby appoint(s) Nancy K. Buese and Andrew L. Schroeder each or any of them, with full power of substitution and revocation, as proxies to represent the undersigned and to vote, as designated, and otherwise act in such proxyholders' sole discretion as to any other matter properly raised in respect of all shares of the common stock of the Corporation, which the undersigned may be entitled to vote at the Special Meeting of Stockholders of MarkWest Hydrocarbon, Inc. to be held on February 21, 2008, at 10:00 a.m. local time at the offices of Hogan & Hartson LLP, One Tabor Center, Suite 1500, 1200 Seventeenth Street, Denver, Colorado 80202, and at any and all adjournments or postponements thereof, with all the rights and powers the undersigned would possess if personally present. Proxies are instructed to vote as specified on the reverse side or in such proxyholders' sole discretion as to any other matter that may properly come before the meeting.
THIS PROXY IS CONTINUED ON THE OTHER SIDE
PLEASE SIGN, DATE AND MAIL THIS PROXY IN THE ENCLOSED ADDRESSED ENVELOPE, WHICH REQUIRES NO POSTAGE IF MAILED IN THE U.S.
Form of Proxy for Holders of MarkWest Hydrocarbon, Inc. Common Stock
THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED.
THE BOARD OF DIRECTORS OF THE CORPORATION RECOMMENDS A VOTE IN FAVOR OF ALL PROPOSALS
MARKWEST HYDROCARBON, INC. 1515 Arapahoe Street Tower 2, Suite 700 Denver, Colorado 80202
THIS PROXY IS CONTINUED ON THE OTHER SIDE