safety safety data sheets investor relations mplx & mwe strategic combination news releases sec filings annual reports & proxy presentations & webcasts historical distributions customer center natural gas ethane and oil marketing ngl marketing services and logistics ngl transportation customer portal retail management services about us code of conduct and ethics quick links current job openings contact us learn more learn more learn more learn more about us markwest a wholly owned subsidiary of mplx lp nyse mplx is engaged in the gathering processing and transportation of natural gas ; the transportation fractionation storage and marketing of ngls ; and the gathering and transportation of crude oil . learn more operations southwest extensive suite of top tier midstream assets throughout liquids rich resource plays northeast largest processor and fractionator in the southern appalachian basin with over 25 years experience marketing ngls throughout the region marcellus six major complexes in the liquids rich marcellus shale the nation s most productive resource play utica largest full service midstream system in the heart of the utica shale ferc pipelines 2016 copyright . markwest energy partners l.p. all rights reserved . privacy policyterms of usesitemap