OZ Minerals Ltd chief executive Andrew Michelmore has rejected criticism of Chinese investment in Australia, saying local resource companies need foreign funds to develop domestic assets.

The resource sector is facing a flood of Chinese investment - including the planned injection of $US19.5 billion ($A28.29 billion) by Aluminium Corporation of China (Chinalco) into Rio Tinto Ltd - that have sparked concerns amongst some local politicians.

But Mr Michelmore says China is the latest in a long list of foreign countries, including Japan and Korea, that have provided funding to develop Australia's resource industry.

"Companies in Australia in the resources industry have forever relied on foreign investment to be able to develop," Mr Michelmore told reporters on Wednesday.

"Australia just does not have the capital to be able develop its own assets."

At issue is the fact that the Chinese groups now acquiring assets and strategic stakes in Australian companies are owned primarily by the Chinese government.

This fact has prompted a number of politicians including, Nationals Senate leader Barnaby Joyce, to raise concerns about the sale of mines to foreign government-controlled entities.

Mr Michelmore's comments came as OZ Minerals on Wednesday agreed to sell the bulk of its assets to China state-owned Minmetals Non-ferrous Metals Company Ltd for $US1.21 billion ($A1.76 billion).

The assets include the Century project in Queensland, the world's second largest zinc mine, the Rosebery zinc mines in Tasmania and the Golden Grove polymetallic mine in Western Australia.

"The fear of a state owned enterprise taking Australia's resources purely back to China - that isn't the situation at all," Mr Michelmore said.

"You need to go right into the detail of what does this mean for the operations and their development and national interest to Australia.

"I think these projected fears of Chinese companies - implying massive numbers of Chinese people coming in, taking control - that is not what is happening."

But, like its bigger rival Rio Tinto, OZ Minerals doesn't require Chinese funds to develop its assets.

It is seeking a much needed financial lifeline to pay off a heavy debt load accrued from an acquisition spree during the last commodities boom.

Without the Chinese investment, OZ Minerals would likely have gone into administration.

So Minmetals' investment in Oz Minerals is about survival, not the development of Australia's resources.

Meanwhile, Minmetals on Wednesday submitted a new proposal to acquire most of OZ Minerals assets, barring Prominent Hill, the Martabe gold project in Indonesia and a portfolio of listed assets.

Mr Andrew Michelmore said the Foreign Investment Review Board (FIRB) would be able to decide on the revised proposal in an "expeditious way".

"I think with the Treasurer's comments last week that the issue was really around Prominent Hill," Mr Michelmore said during a teleconference.

"(The) FIRB should be a in a very good position to be able to deal with this revised application now that it doesn't have Prominent Hill in it."

The FIRB has already allowed Hunan Valin Iron and Steel Group to lift its stake in Fortescue to 17.55 per cent through a $645 million equity investment, and is still assessing Aluminium Corporation of China's (Chinalco) proposed $US19.5 billion ($A28.3 billion) investment in Rio Tinto.

"We believe the Australian government can deal with this expeditiously as much of the material has already been considered," Minmetals spokesman Ian Smith said in a statement.

After the completion of the Minmetal's deal, OZ Minerals expects to have about $600 million in cash after using the proceeds to retire all of its debt, barring a $US105 million ($A152.32 million) convertible bond.

"This looks like a great get out of jail card," Credit Suisse analyst Michael Slifirski said during a teleconference.

The revised deal also allowed OZ Minerals to get a extension from its bankers for a deadline to refinance $1.3 billion of debt facilities by another month from Wednesday to April 30.

Minmetals had originally offered 82.5 cents cash per OZ Minerals share, or $2.6 billion for the entire company and its assets, including Prominent Hill.

The original offer would have seen OZ Minerals delisted from the Australian stock exchange and become a subsidiary of Minmetals.

But the new proposal provides the miner with an operating mine and the option to remain listed.

The latest offer is subject to both FIRB and OZ Minerals shareholder approval and is expected to be concluded by June.

Mr Michelmore also said the company was continuing with its plan to sell the Martabe project, which OZ Minerals put up as security against a $140 million bridging finance loan set up in January, at a realistic price.

"It's still an asset up for sale, we are continuing with that process," Mr Michelmore said during a teleconference.

"There is no way we will be selling it for a fire sale price."