Chinese private equity firm Cathay Fortune Corp has made an $850 million offer for Australia-listed Discovery Metals, Dow Jones Newswires reported Thursday, as China's copper demand continues to grow.

The Shanghai-based firm is teaming up with the China-Africa Development Fund, an investment fund specialising in Africa, in the bid for Discovery Metals, which is focused on copper mining in Botswana, it reported.

The agency quoted a statement from Cathay Fortune.

The deal has received regulatory approval from the National Development and Reform Commission, China's economic planning agency, it said.

China buys 38 percent of the world's copper, making it by far the world's biggest purchaser.

The world's second-largest economy increasingly needs copper as it continues to expand and upgrade its industry, and demand is forecast to remain strong despite a recent slowing in Chinese economic growth rates.

Steep falls in some commodity prices -- largely due to weakening demand amid China's economic slowdown -- have driven down the stock prices of many mining companies, prompting speculation of a wave of deals.

Copper prices have remained robust, however, amid supply concerns.

Dow Jones quoted a Discovery Metals official as saying the offer was being considered by the company's board.

Cathay Fortune owns 75 percent of the bid vehicle, the report added, with the remainder held by the China-Africa Development Fund.

Cathay Fortune already has a 13.7 percent stake in Discovery Metals.

Previous Chinese attempts to buy stakes in Australia's mining firms sparked intense debate in the country over whether to allow Chinese state entities to increase their control over its resources.