BHP Billiton Limited discovers, acquires, develops, and markets natural resources worldwide. It operates through Petroleum and Potash, Copper, Iron Ore, and Coal segments. The company explores for, develops, produces, and markets oil and gas with operating assets in the deep water Gulf of Mexico, Western Australia, Trinidad and Tobago, the United Kingdom, and Pakistan; and owns the Jansen potash project located in the Saskatchewan potash basin in Canada. It also explores for copper, silver, lead, zinc, molybdenum, uranium, gold, iron ore, and seaborne metallurgical and thermal coal. The company was formerly known as BHP Limited and changed its name to BHP Billiton Limited in July 2001. BHP Billiton Limited was founded in 1851 and is headquartered in Melbourne, Australia. BHP Billiton Limited operates as a subsidiary of BHP Billiton Group.