NRG Energy Inc., of Princeton, has agreed to shut down its coal-fired Portland Generating Station in Mount Bethel, Pa., six months earlier than scheduled to settle a federal lawsuit over its emissions.

NRG, which acquired the plant in December as part of its merger with GenOn Energy Inc., will close the plant by June 1, 2014, rather than January, 2015. The closure ends a lawsuit brought by the states of New Jersey and Connecticut for alleged noncompliance with the federal Clean Air Act.

The 570 MW plant is located 26 miles northeast of Bethlehem, Pa., on the Delaware River.