BHP Billiton is a global mining, oil and gas company headquartered in Melbourne, Australia and with a major management office in London, United Kingdom. It is the world's largest mining company measured by revenue and, as of February 2011, the world's third-largest company measured by market capitalisation.
BHP Billiton was created in 2001 through the merger of the Australian Broken Hill Proprietary Company Limited (BHP) and the Anglo-Dutch Billiton plc. The result is a dual-listed company. BHP Billiton Limited, which is the majority partner, has its primary listing on the Australian Securities Exchange and is the largest company in Australia measured by market capitalisation. BHP Billiton Plc has its primary listing on the London Stock Exchange and is a constituent of the FTSE 100 Index.