BHP Billiton has joined Rio Tinto in reassessing projects in Australia as the nation considers a 40% super profit resource tax of the Government of Australia.

BHP Billiton chief executive officer Marius Kloppers told Bloomberg it would be difficult for the company to approve expansion plans, including projects at its Olympic Dam Uranium mine if the tax went ahead.

The Olympic Dam copper, gold and uranium mine at South Australia has been earmarked for a $16bn expansion which would allow BHP to increase copper output almost fourfold, boost gold production eightfold and uranium production by almost five times.

BHP’s Kloppers said the tax could lead to mining companies shifting their projects to other countries where less tax is to be paid.

He said plans to join BHP and Rio’s iron ore operations in Western Australia, however, shouldn’t be derailed by the tax.

Meanwhile, China is also considering a similar but smaller levy on mining companies there, according to state-run newspaper China Daily.