Two heads (or headquarters) are better than one. Aussie minerals and oil company BHP Limited acquired UK miner Billiton plc in 2001. The result: a two-headquartered, dual-listed company run as a single entity with the same board of directors and management. The Melbourne side is BHP Billiton Limited, the London side is BHP Billiton Plc; collectively they are known as BHP Billiton. One of the largest diversified natural resources companies, it ranks among the world's top producers of iron ore and coal (thermal and metallurgical). Other products include aluminum, copper, manganese, nickel, silver, uranium, and potash. BHP also has crude oil and natural gas holdings.