The deal involving Mitsubishi Material’s purchase of a 25% stake in Copper Mountain Mining’s project in British Columbia, Canada, has formally closed.

The companies had previously signed an agreement for the purchase in which Mitsubishi also agreed to buy all the copper concentrate produced from the mine.

The project’s current resource is estimated at five billion pounds of copper at 0.15% Cu cut off, based on Copper Mountain’s 2007 and 2008 exploration programmes.

The open pit porphyry copper mine produced 1.74 billion pounds of copper, 730,000oz of gold and 9.1 million ounces of silver between 1972 and 1996, Copper Mountain said.

Copper Mountain’s goal is to develop the Copper Mountain project as a mid-tier copper and precious metal mine to produce approximately 100 million pounds of copper a year by mid 2011, the company said.