Under the deal, MarkWest Utica will provide gathering, processing, fractionation and marketing services in the liquids-rich corridor of the Utica, and build natural-gas gathering infrastructure in Harrison, Guernsey and Belmont counties.

The company will develop about 60 miles of gas gathering pipelines and associated compression to move Gulfport gas volumes by the end of 2012, and 140 miles of gathering pipelines by the first quarter of 2014.

MarkWest chairman, president and chief executive officer Frank Semple said, "The construction of this extensive set of midstream facilities is the first step of our Utica development plan, which will provide full service integrated services for our producer customers."

MarkWest Utica will initially bring online an interim 40 million cubic feet per day (MMcf/d) refrigeration natural gas processing plant at its Harrison processing complex, with an expected third quarter 2012 completion date.

Further, Harrison I, a 125 MMcf/d cryogenic gas processing facility, which is expected to begin operations by the first quarter of 2013 will be developed.

In fourth quarter of 2012, MarkWest Utica will develop a second processing complex in Noble County, which will initially have 45 million cubic feet per day natural-gas processing capacity, and a 200 million cubic feet per day cryogenic processing plant is planned to be built in mid-2013.

The Harrison and Noble processing complexes will be connected through a NGL gathering system to the Harrison fractionation complex, which will include 100,000 barrels per day of C2+ fractionation capacity by the first quarter of 2014.

MarkWest Liberty Midstream and MarkWest Utica will jointly own the Harrison fractionation complex.