Australian Prime Minister Julia Gillard Thursday welcomed surprise backing from BHP Billiton, the world's biggest mining company, for a carbon tax to ease pollution.

Gillard, whose fragile coalition includes the environment-focused Greens party, said the comments from BHP chief executive Marius Kloppers chimed with government plans.

"I welcome the statements today from Mr Kloppers," Gillard said.

"Obviously many members of the business community, Mr Kloppers included, have made statements and have called over quite a long period of time now for governments to deal with the question of pricing carbon.

"It's absolutely no secret ... that the government believes we need to work towards a price on carbon."

Kloppers Wednesday urged Australia, the world's biggest per capita polluter, to lead the way by taxing carbon emissions blamed for global warming, rather than waiting for concerted international action through the United Nations.

He called for revenue raised from carbon taxing to be returned to businesses and the community, and for trade-exposed industries to be exempted until a global system was in place.

The comments were unexpected as BHP has four coal mines in Australia and recorded revenues of more than 10 billion US dollars worldwide from its coal businesses in the last financial year.

Greens leader Senator Bob Brown also praised Kloppers' speech, which comes as the government prepares to set up a climate change committee of MPs and experts to work towards pricing carbon emissions.

"Mr Kloppers' very timely statement yesterday -- which is based on pure common sense -- will give strength to this committee, as it deliberates on the best way forward to a carbon price for Australia," he told public broadcaster ABC.

Emissions-trading legislation twice failed and was shelved by ex-leader Kevin Rudd this year, prompting a fall in his ratings which brought Gillard to power in a party revolt in June.

Australia's general election in August ended in a hung parliament with neither major party winning an outright majority, while the Greens enjoyed a record share of the vote.