Some of Australia's biggest resource companies could lose a major investor if Norway goes through with a plan to ban its famous sovereign wealth fund from investing in coal, oil and gas.

Norway's sovereign wealth fund is the world's biggest at $840 billion and is a major shareholder in companies such as BHP Billiton, Woodside Petroleum and Whitehaven Coal.

A non-government majority in the Norwegian parliament had been edging towards a vote on banning the fund from investing in coal, and the pressure has forced the government to launch a year-long expert review into whether the fund should cease investing in all forms of fossil fuel.

The fund is already banned from investing in tobacco and weapons, and it sold out of 27 mining companies during 2013.

Aside from Australia's big resources companies, the fund is also a shareholder in Glencore Xstrata and Anglo American, as well as the world's biggest petroleum companies including Shell, ExxonMobil, BP and Chevron.