Overseas Shipholding Group, Inc., a tanker company, primarily engages in the ocean transportation of crude oil and petroleum products. The company owns and operates a fleet of oceangoing vessels that engages in the transportation of liquid cargoes in the United States flag trades and international markets. It is involved in the bulk shipping of crude oil and refined petroleum products to independent and state-owned oil companies, oil traders, refinery operators, and the United States and international government entities. As of December 31, 2011, the company owned and operated a fleet of 111 double-hulled vessels, including 89 vessels operated in the international markets and 22 operated in the United States flag markets. Overseas Shipholding Group, Inc. was founded in 1948 and is headquartered in New York, New York.