Potomac Edison Company (The). The Group's principal activities are the generation, transmission and distribution of electric power. The Group is a wholly owned utility subsidiary of Allegheny Energy, Inc and is a part of the Allegheny Energy integrated electric utility system. The Group serves about 411,600 customers in Maryland and Virginia. The principal industries served are the ones producing aluminum, cement, fabricated products, rubber products, sand, stone, and gravel. Residetial accounted for 40% of 2001 revenues; industrial, 25%; commercial, 19%; transmission services and bulk power, 8% and wholesale and other, 8%.