KeySpan Corporation, through its subsidiaries, operates as a gas utility company in the United States. It operates through four segments: Gas Distribution, Electric Services, Energy Services, and Energy Investments. The Gas Distribution segment distributes natural gas to customers in New York, Massachusetts, and New Hampshire. As of December 31, 2006, it served approximately 2.6 million customers. The Electric Services segment manages electric transmission and distribution system owned by Long Island Power Authority (LIPA); provides generating capacity and energy conversion services for LIPA; and manages fuel supplies for LIPA. This segment also owns, leases, and operates the 2,200 megawatt Ravenswood electric generation facility located in Queens County in New York City, and the 250 megawatt combined cycle generating unit. In addition, it provides retail marketing of electricity to commercial customers. The Energy Services segment provides energy-related services to customers primarily in the New York City and Boston metropolitan areas. Its services include service and maintenance of energy systems and appliances; and operation and maintenance, design, engineering, consulting, and fiber optic services to commercial, institutional, and industrial customers. The Energy Investments segment includes gas production and development activities, domestic pipelines, gas storage facilities, and liquefied natural gas facilities and operations. The company was founded in 1895 and is headquartered in Brooklyn, New York. As of August 24, 2007, KeySpan Corp. is a subsidiary of National Grid plc.