MarkWest Energy Partners, L.P. (NYSE: MWE) announced today that Frank Semple, Chairman, President and Chief Executive Officer, will present at the National Association of Publicly Traded Partnerships (NAPTP) 2014 Master Limited Partnership (MLP) Investor Conference at 10:45 a.m. Eastern Time on Wednesday, May 21, 2014, at the Sawgrass Marriott in Ponte Vedra Beach, Florida. Interested parties can listen to a live webcast of the presentation and download the related presentation materials by visiting the company’s website at www.markwest.com under "Investor Relations / Presentations.” A replay of the webcast will be archived on the site shortly after the presentation has concluded and will be available for 7 days. 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.