Global miner Rio Tinto announced on Monday that it has agreed to sell 80 percent stake in its Northparkes copper and gold mine in New South Wales, Australia, to China Molybdenum for $820 million.

"Northparkes is a successful business but is not of sufficient size to be a good fit with our strategy," Rio Tinto chief financial officer Chris Lynch said in a statement released on Monday.

Rio Tinto said the mine will have a strong future under its new ownership.

"Rio Tinto will continue to manage Northparkes to the highest safety and environmental standards during the transition to the new owner," said Lynch.

The deal is conditional upon customary regulatory approvals and the approval of China Molybdenum shareholders.

Rio Tinto said it had received binding commitments from the two major shareholders of China Molybdenum to support the deal.

The transaction is expected to close by the end of 2013.

China Molybdenum is the world's fourth largest producer of molybdenum and the second largest tungsten concentrate manufacturer.