Mining giant BHP Billiton has announced it has signed a final agreement for the sale of its Pinto Valley copper mining operations in Arizona to Vancouver based Capstone Mining Corp for US$650 million.

Subject to final regulatory approval, the sale of the asset will also include the San Manuel Arizona Railroad Company (SMARRCO), with final approval expected to be granted sometime over the second half of the 2013 calendar year.

The Pinto Valley Mine is located in the Globe-Miami mining district in Arizona, approximately 125 kilometres east of Phoenix. It is projected to produce 130 - 150 million pounds of copper in concentrate and approximately 10 million pounds of copper cathode annually.

BHP Billiton President Copper, Peter Beaven, said: “The sale of Pinto Valley is an excellent outcome for BHP Billiton shareholders. It is consistent with our strategy and it takes the transaction value of divestments announced over the last 12 months to US$5.0 billion. We are pleased to have reached agreement with Capstone, particularly given their commitment to maintain our environmental and safety standards."