According to Cochilco, the world market for refined copper will have a deficit this year of 67,000 tonnes.

The Fraser Institute's Annual Survey of Mining Companies places Western Australia second, and the Canadian province of Saskatchewan third.

The due diligence period on the offer ends May 11.

Barrick CEO Mark Bristow is refusing to shut the door on accepting new investment from state-controlled Chinese companies, and questioned the move by Canada and the US to clamp down on such investment.

A Reuters poll showed that prices are due to recover slightly, supported by low inventories.

“We’re certainly learning from it and watching how that progresses,” said Mark Bristow.

Wood Mackenzie estimates a greener world will be short about six million tonnes of copper by next decade.

Freeport will also be required to build a smelter in Papua.