(REUTERS) -- Chinese gold and copper miner Zijin Mining Group Co Ltd reported on Friday an estimated 5.8 billion yuan ($919.58 million) profit for 2011, up 20 percent from the prior year.

In a filing to the Hong Kong bourse, Zijin said operating revenue rose 39.5 percent year on year to 39.82 billion yuan with total assets increasing 38.8 percent to 53.29 billion yuan.

The increase in revenue and profits was driven by higher prices for products such as gold, it said.

Its audited consolidated annual results are expected to be announced in March.

Zijin posted a 35 percent rise in net profit to 4.8 billion yuan in 2010.