|BHP Billiton Limited is a diversified natural resources company. The Company operates nine customer sector groups (CSGs): petroleum, aluminium, base metals (including uranium), diamonds and specialty products, stainless steel materials, iron ore, manganese, metallurgical coal and energy coal. During the fiscal year ended June 30, 2010 (fiscal 2010), the Company realized an annual production volume of 158.56 million barrels of oil equivalent. During fiscal 2010, the company produced 1.2 million tonnes of aluminium. It also produced 13.9 million tonnes of bauxite and 3.8 million tonnes of alumina. On March 23, 2010, the Company completed the acquisition of Athabasca Potash Inc (API). In July 2011, BHP Billiton Limited acquired Petrohawk Energy Corp. In September 2011, the Company acquired Leighton Holdings Limited's Pilbara Contracting Unit.