MarkWest Energy Partners Announces 2009 Annual Meeting of Unitholders

DENVER--(Business Wire)--
MarkWest Energy Partners, L.P. (NYSE:MWE) announced today that its 2009 Annual
Meeting of Unitholders will be held on Tuesday, June 2, 2009, at 10:00 a.m. MDT,
at MarkWest`s headquarters located at 1515 Arapahoe Street, Tower 2, Suite 700,
Denver, Colorado, 80202. The record date for determination of unitholders
entitled to vote at the meeting was April 7, 2009.

Additional information, including details of the business to be conducted at the
annual meeting, is included in the Partnership`s Notice of Annual Meeting and
Proxy Statement, which was filed with the Securities and Exchange Commission.
The proxy statement and the Partnership`s 2009 Annual Report may be accessed
through the investor relations section of the Partnership`s website at
www.markwest.com.

MarkWest Energy Partners, L.P. is a master limited partnership engaged in the
gathering, transportation, and processing of natural gas; the transportation,
fractionation, marketing, and storage of natural gas liquids; and the gathering
and transportation of crude oil. MarkWest has extensive natural gas gathering,
processing, and transmission operations in the southwest, Gulf Coast, and
northeast regions of the United States, including the Marcellus Shale, and is
the largest natural gas processor in the Appalachian region.

This press release includes "forward-looking statements."All statements other
than statements of historical facts included or incorporated herein may
constitute forward-looking statements.Actual results could vary significantly
from those expressed or implied in such statements and are subject to a number
of risks and uncertainties.Although we believe that the expectations reflected
in the forward-looking statements are reasonable, we can give no assurance that
such expectations will prove to be correct.The forward-looking statements
involve risks and uncertainties that affect our operations, financial
performance, and other factors as discussed in our filings with the Securities
and Exchange Commission.Among the factors that could cause results to differ
materially are those risks discussed in the periodic reports we file with the
SEC, including our Annual Report on Form 10-K for the year ended December 31,
2008, and our Quarterly Report on Form 10-Q for the three months ended March 31,
2009, as filed with the SEC.You are urged to carefully review and consider the
cautionary statements and other disclosures made in those filings, specifically
those under the heading "Risk Factors."We do not undertake any duty to update
any forward-looking statement except as required by law.

MarkWest Energy Partners, L.P.
Frank Semple, 866-858-0482
Chairman, President & CEO
or
Nancy Buese, 866-858-0482
Senior VP & CFO
or
Andy Schroeder, 866-858-0482
VP Finance & Treasurer
investorrelations@markwest.com

Copyright Business Wire 2009