MPLX is a publicly traded master limited partnership formed by Marathon Petroleum Corporation (MPC) 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.
In 2015, MPLX merged with MarkWest, whereby MarkWest became a wholly owned subsidiary of MPLX. MarkWest is one of the largest processors of natural gas in the U.S. and the largest processor and fractionator in the Marcellus and Utica shale plays. The company’s midstream energy operations include: natural gas gathering, processing and transportation; NGL gathering, transportation, fractionation, storage and marketing; and crude oil and refined products transportation and storage. Its integrated midstream energy asset network links producers of natural gas, natural gas liquids and crude oil from some of the largest supply basins in the United States to domestic and international markets.