BHP Billiton plc is the London corporate office for BHP Billiton Group. Though its shareholders differ from BHP Limited it shares direct control of the company with Australia based BHP Limited (board of directors and management however only a minority of them are appointed from BHP Billiton plc due to its smaller market value). The plc designation came from before the 2001 merger of BHP and Billiton when Billiton had its central office in London. BHP Billiton plc is listed on exchanges in London, USA and South Africa. BHP Billiton's market cap is about 20% smaller than its counterpart BHP Billiton.
The division, the British part of the enlarged company is the source of much of BHP Billiton's present coal, aluminum and titanium operations. The larger BHP contributed the oil, copper and diamond businesses.(Read more at Wikinvest )