MPLX LP Increases Quarterly Distribution

FINDLAY, Ohio, April 30, 2013 - MPLX LP (NYSE: MPLX) today announced a cash distribution of $0.2725 per common unit for the first quarter of 2013. This represents an increase of $0.01 per common unit above the minimum quarterly distribution. The distribution will be paid May 17, 2013, to unitholders of record May 10, 2013. This release is intended to be a qualified notice under Treasury Regulation Section 1.1446-4(b). Brokers and nominees should treat 100 percent of MPLX's distributions to foreign investors as being attributable to income that is effectively connected with a United States trade or business. Accordingly, MPLX's distributions to non-United States investors are subject to federal income tax withholding at the highest applicable effective tax rate. # # # About MPLX LP MPLX is a fee-based, growth-oriented master limited partnership formed in 2012 by Marathon Petroleum Corporation to own, operate, develop and acquire pipelines and other midstream assets related to the transportation and storage of crude oil, refined products and other hydrocarbon-based products. Headquartered in Findlay, Ohio, MPLX's assets consist of a majority equity interest in a network of common carrier crude oil and products pipeline assets located in the Midwest and Gulf Coast regions of the United States and a 100 percent interest in a butane storage cavern located in West Virginia. Investor Relations Contacts: Pamela Beall (419) 429-5640 Beth Hunter (419) 421-2559 MPLX XP Distribution: http://hugin.info/155038/R/1697645/559560.pdf This announcement is distributed by Thomson Reuters on behalf of Thomson Reuters clients. The owner of this announcement warrants that: (i) the releases contained herein are protected by copyright and other applicable laws; and (ii) they are solely responsible for the content, accuracy and originality of the information contained therein. Source: MPLX LP via Thomson Reuters ONE [HUG#1697645]