May 2 (Bloomberg) -- Australia will impose a 40 percent tax on the profits of resource companies like BHP Billiton Ltd. and Rio Tinto Group to pay for infrastructure, retirement and company levy changes as part of the broadest overhaul of its tax system since the Second World War.

The government, commenting on Treasury Secretary Ken Henry’s 10-year tax plan, said the tax would start in 2012 and raise A$12 billion ($11.1 billion) in the first two years. The move to better tap into the nation’s mining boom, fueled by commodities demand from China and India, comes as Prime Minister Kevin Rudd prepares for an election later this year.

“This will use super profits on resources owned by all Australians,” Rudd told reporters in Canberra, saying he’s prepared for a backlash to the measures. “This will help convert Australia’s strong economic position today into enduring prosperity.”

The changes set up a potential clash between Rudd and resources companies that make up 9 percent of the economy and last week warned that a 40 percent levy and double taxation with state royalties would threaten $108 billion worth of planned investment.

“If implemented, these proposals seriously threaten Australia’s competitiveness, jeopardize future investments and will adversely impact the future wealth and standard of living of all Australians,”