MPLX LP Announces Formation of Strategic Joint Venture with Antero Midstream Partners LP

• MarkWest Energy Partners, L.P., a wholly owned subsidiary of MPLX LP, and Antero Midstream Partners LP have formed a strategic joint venture to support Antero Resources Corporation in the Marcellus Shale.
• Antero Midstream Partners will release to the joint venture its dedication from Antero Resources Corporation of approximately 195,000 gross operated acres located in Tyler, Wetzel and Ritchie counties of West Virginia.

The joint venture will support the ongoing development of incremental gas processing required by Antero Resources Corporation in the Marcellus Shale.

The joint venture is investing in fractionation capacity at MarkWest's Hopedale Complex in Ohio and has an option to invest in future fractionation expansions that support Antero Resources Corporation's liquids production.

FINDLAY, Ohio, Feb. 6, 2017 - MPLX LP (NYSE: MPLX) today announced that its wholly owned subsidiary, MarkWest Energy Partners, L.P., and Antero Midstream Partners LP (NYSE: AM) have formed a strategic joint venture to support the development of Antero Resources Corporation's (NYSE: AR) extensive Marcellus Shale acreage in the prolific rich-gas corridor of West Virginia.

The joint venture is owned 50 percent by MarkWest and 50 percent by Antero Midstream and is supported by a long-term, fee-based agreement with Antero Resources. As part of this agreement, Antero Midstream has agreed to release to the joint venture its 195,000 gross acre processing dedication from Antero Resources, increasing the Marcellus Shale area dedication to MarkWest from approximately 167,000 gross operated acres to over 360,000 gross operated acres. The additional dedicated acreage includes Antero Resources' core Marcellus Shale position in Tyler, Wetzel, and Ritchie counties of West Virginia.

To support Antero Resources' significant production growth profile, the joint venture will expand processing infrastructure at its Sherwood Complex in Doddridge County, West Virginia. The Sherwood Complex began operations in October 2012 and has grown to become the single largest gas processing complex in the Northeast, currently with six cryogenic processing facilities totaling 1.2 billion cubic feet per day of capacity.

Ongoing development of gas processing infrastructure at the Sherwood Complex includes three new joint venture processing facilities, totaling 600 million cubic feet per day of incremental capacity for Antero Resources. The joint venture expects to commence operations of two of the new facilities during the first quarter and third quarter of 2017, and the third new facility during the first quarter of 2018. In addition to the three new processing facilities, the joint venture contemplates the development of up to another eight processing facilities to support Antero Resources, which would be located at both the Sherwood Complex and a new location in West Virginia.