Marathon Ashland Pipe Line LLC, a wholly owned unit of MAP, will serve as operator of the pipeline system. MAP is owned 62% by Marathon Oil Co.—a part of Marathon Oil Corp.—and 38% by Ashland Inc.

The 795-mile (1,279 km) Texas-to-Illinois refined products pipeline can move up to 210,000 barrels per day, but has been largely empty since mid-2011. Marathon operates the line and Enterprise is ...