MarkWest Energy Partners Announces Filing of Definitive Proxy Statement

DENVER--(BUSINESS WIRE)--MarkWest Energy Partners, L.P. (the “Partnership”) (NYSE: MWE) today announced that it has filed a definitive proxy statement and prospectus with the U.S. Securities and Exchange Commission regarding the pending merger pursuant to which the Partnership would become a wholly owned subsidiary of MPLX LP (“MPLX”) (NYSE: MPLX). A special meeting of the common unitholders has been set to approve the previously announced Agreement and Plan of Merger, dated as of July 11, 2015, by and among the Partnership, MPLX, MPLX GP LLC, the general partner of MPLX, Sapphire Holdco LLC, a wholly owned subsidiary of MPLX, and, for certain limited purposes, Marathon Petroleum Corporation.