Canberra :  Australia's treasurer Wayne Swan, speaking ahead of the release of a major review of the nation's tax system today, said "extremely profitable" mining companies are paying proportionally less tax than a decade ago.

"There are some figures worth bearing in mind when it comes to mining taxes," Swan said yesterday. "At the beginning of the 2000s, or around that date, something like one in three dollars in mining profit was returned to the Australian people. Now it's more like one in seven."

Swan is due to release the government's response to treasury secretary Ken Henry's 10-year plan for a more efficient tax system in Canberra today. Media speculation has focused on a resource rent tax that would be levied on the profits of mining companies such as BHP Billiton and Rio Tinto Group, according to Stephen Walters, chief economist at JPMorgan Chase in Sydney.

"Mining companies have been extremely profitable in recent times," Swan told reporters in Canberra. "But, as I said before, when it comes to state mining taxes they have dropped dramatically as a share of those mining profits. So that's just one issue which is considered in the report."

The government commissioned the review almost two years ago and it was handed to Swan at the end of last year. It aims to eliminate many of the 125 local, state and federal taxes currently in place. Of that total, 10 taxes, including state mining and petroleum rent tax, reap 90 per cent of revenue.

Mining companies say a resource rent tax would jeopardise investment and jobs in an industry that makes up about a tenth of Australia's A$1.21 trillion (Dh4.12 trillion) economy and employs about 333,000 people.

Swan said the government's response to the so-called Henry Review would be about making sections of the economy pay their "fair share".

Economic growth in Australia, one of few nations to skirt last year's global recession, will accelerate to 3.5 per cent in 2011 from 3 per cent this year, the International Monetary Fund said last week.

State levies on way out

A national tax on miners would replace a web of earnings-based royalties set by state governments. The review due today may show that Australia faces a A$35 billion (Dh119.4 billion) shortfall in taxes from commodity companies, the Australian Financial Review reported yesterday, without disclosing where it obtained the information.

A 40 per cent resource rent tax could cut the earnings of Rio Tinto by as much as 30 per cent and BHP Billiton's by 19 per cent, according to Merrill Lynch.