MarkWest Energy Partners, L.P. (NYSE: MWE) (“MarkWest” and “the Partnership”) today announced that Keith E. Bailey has elected to retire from the Board of Directors of the Partnership’s General Partner, MarkWest Energy GP, LLC, effective June 6, 2014, the date of the Partnership’s 2014 Annual Meeting of Common Unitholders. Mr. Bailey has served as a member of the Board of Directors since January 2005. Mr. Bailey is currently serving as Chairman of the Board’s Compensation Committee and is also on the Board’s Nominating and Corporate Governance Committee.

“On behalf of MarkWest, I would like to thank Keith for his service over the past nine years. His guidance and leadership has played an influential role in establishing MarkWest as a leading growth-oriented master limited partnership,” stated Frank Semple, Chairman, President and Chief Executive Officer of MarkWest. “He served a key role in the ongoing development of our strategic vision to deliver top-tier midstream services and innovative customer-focused solutions. We wish Keith the best in his future endeavors.”

In conjunction with Mr. Bailey’s upcoming retirement, the Partnership is pleased to announce that William A. Bruckmann III has been nominated to stand for election to serve as a member of the General Partner’s Board of Directors at the Partnership’s Annual Meeting of Common Unitholders on June 6, 2014. Mr. Bruckmann’s professional career consists of extensive energy and investment-related experience. He has served as Director of Duncan Energy Partners, L.P. from February 2007 to September 2011 and Director of Williams Energy Partners, L.P. (now Magellan Midstream Partners, L.P.) from March 2001 to June 2003. He has been self-employed as a consultant since October 2000 and previously held positions in investment and corporate banking with Manufacturers Hanover, Chemical Securities, and Chase Securities.

“We are very excited to offer Bill the opportunity to be elected as the newest member of our board,” commented Frank Semple. “His prior natural gas pipeline and midstream experience, coupled with strong capital markets expertise, will be instrumental as we continue to execute on our growth strategy and deploy capital investments to support producers in many of America’s most productive and exciting resource plays.”

MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of natural gas liquids; and the gathering and transportation of crude oil. MarkWest has a leading presence in many unconventional gas plays including the Marcellus Shale, Utica Shale, Huron/Berea Shale, Haynesville Shale, Woodford Shale and Granite Wash formation.

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 MarkWest believes that the expectations reflected in the forward-looking statements are reasonable, MarkWest can give no assurance that such expectations will prove to be correct. The forward-looking statements involve risks and uncertainties that affect operations, financial performance, and other factors as discussed in filings with the Securities and Exchange Commission (SEC). Among the factors that could cause results to differ materially are those risks discussed in the periodic reports filed with the SEC, including MarkWest’s Annual Report on Form 10-K for the year ended December 31, 2013. 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.” MarkWest does not undertake any duty to update any forward-looking statement except as required by law.