MarkWest Energy Partners, L.P. (NYSE:MWE) reported that Frank Semple, Chairman, President and CEO, will present at the National Association of Publicly Traded Partnerships (NAPTP) 2012 Master Limited Partnership Investor Conference at 4:30 p.m. Eastern Time on Wednesday, May 23, 2012, at the Hyatt Regency Greenwich in Old Greenwich, Connecticut.

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