Marathon Petroleum Corporation Chairman, President and Chief Executive Officer Gary R. Heminger announced changes in the senior management structure of the general partner of MPLX LP, MPC's master limited partnership, and MarkWest Energy Partners, L.P., a wholly owned subsidiary of MPLX. The changes will be effective Oct. 1, 2016. Randy S. Nickerson, who currently serves as Marathon Petroleum Corporation's executive vice president, Corporate Strategy, will be appointed executive vice president and chief commercial officer, MarkWest Assets, of MPLX's general partner. In this incremental role, he will serve as an officer of MPLX and report to Templin. Nickerson will continue in his role to develop overall strategy around midstream assets as they relate to MarkWest, MPLX and Marathon Petroleum Corporation. He will remain in Denver.