Tax deal will save firms billions, says richest Aussie

A tax deal between Australia's three biggest miners and the federal Government will save those companies more than A$100 billion ($124 billion) in tax, the nation's richest man says.

Fortescue Metals Group chief Andrew Forrest told ABC TV the deal struck between the big miners and Prime Minister Julia Gillard would create at least a $100 billion tax shelter for those companies.

Upon becoming PM, Ms Gillard made a deal with BHP Billiton, Rio Tinto and Xstrata to change a so-called super profits tax touted by former prime minister Kevin Rudd.

The changes included removing a retrospectivity clause, reducing the companies impacted and increasing the threshold at which it took effect.

The tax, renamed the mineral resources rent tax, was endorsed by the three mining giants, but has been opposed by some small and mid-tier mineral producers, including Fortescue.

Forrest, Australia's wealthiest man, said the tax compromise was unfair.

He is backing an advertising campaign by the Association of Mining and Exploration Companies against the tax.

Forrest said Rudd had planned to produce a discussion paper on changes to the super profits tax to get feedback over a period of months, and that was what Gillard should do.

- AAP