On August 28, 2017, Paula L. Rosson, Senior Vice President and Chief Accounting Officer of MPLX GP LLC and principal accounting officer of MPLX LP (the “Partnership”) informed the Partnership that she has elected to remain in the Partnership’s Denver, Colorado division office and accept a senior management role with MarkWest Energy Partners, L.P., a wholly-owned subsidiary of the Partnership. Ms. Rosson’s election to remain in Denver is in lieu of relocating to the Partnership’s headquarters in Findlay, Ohio to continue service as the Partnership’s principal accounting officer long term. In the interim, Ms. Rosson will continue to serve as the principal accounting officer of the Partnership until a successor is appointed.

About MPLX LP (NYSE:MPLX)

MPLX LP is a United States-based diversified master limited partnership (MLP) company, which owns, operates, develops and acquires midstream energy infrastructure assets. The Company is engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of natural gas liquids (NGLs); and the gathering, transportation and storage of crude oil and refined petroleum products. The Company’s segments are Logistics and Storage (L&S) and Gathering and Processing (G&P). Its assets include infrastructure to support Marathon Petroleum Corporation (MPC), including approximately 2,900 miles of crude oil and refined product pipelines across over nine states. The Company owns a barge dock facility with approximately 80 thousand barrels per day (mbpd) of crude oil and product throughput capacity, as well as crude oil and product storage facilities with approximately 4,530 thousand barrels (mbbls) of available storage capacity.