China Molybdenum Co has made another step closer to its planned acquisition of Rio Tinto's 80% stake in the Australian Northparkes copper and gold mine after receiving the go-ahead from the mine's joint venture partner Sumitomo Metal Mining, the Chinese molybdenum producer said in a filing to the Shanghai Stock Exchange Tuesday.

The Henan-based producer said it received a notice from Rio Tinto subsidiary North Mining on Monday that Japan's Sumitomo Metal Mining has given up priority purchase rights to the 80% stake in Northparkes and agreed to CMOC's purchase.

Sumitomo holds a 20% stake in Northparkes through its Sydney-based group company SC Mineral Resources and Rio Tinto's 80% interest is held by its subsidiary North Mining.

CMOC's wholly-owned subsidiary CMOC Mining signed a purchase agreement on July 26 to buy Rio Tinto's 80% interest in Northparkes for $820 million. The sale is subject to Sumitomo's approval as well as regulatory approvals.

"The company is keeping an eye on the progress of the matter, and would make announcements in accordance with the rules," CMOC said in the statement.

In August, CMOC received approval from China's National Development and Reform Commission for the planned purchase, Platts reported previously.

CMOC had said the mine acquisition would help it extend its business to the copper and gold sectors, with immediate cash flows from the copper and gold businesses.

Located in central New South Wales, Northparkes is 80% owned by Rio Tinto and 20% by Japan's Sumitomo. It has the capacity to produce around 160,000 mt/year of copper and 50,000 oz/year of gold.