Chinalco Overseas Holdings president Wang Wenfu said the deal was not well understood, nor was the level of competition between China's state-owned enterprises.
The deal would provide relatively cheap funding from Chinese banks, he said.
Speaking to The Australian in Beijing yesterday, Mr Wang, one of the key architects of the deal, said Chinalco would listen to shareholders in the Anglo-Australian company.
The Chinese group was not a customer of Rio and had a vested interest in Rio getting a good price for its iron ore, he said.
"We are committed to delivering the current deal, but we are listening to shareholders and their concerns," Mr Wang said.
In London and Australia as well as China there has been growing dissatisfaction with the deal, with institutional shareholders in Britain publicly agitating against the proposal.
There has been increasing speculation that Chinalco would be prepared to cut a deal to save the transaction, but Mr Wang said he believed the deal spoke for itself about its value to Rio and to Australia.
"We are pressing home our rights under this deal in the same way that any western company investing $US19.5 billion in another company would be."
In recent months, as global stock markets have rallied by 25-30 per cent, some of Rio's shareholders have accused the company's board of giving away the family silver to China and seeking access to rights on the same terms, but Mr Wang defended the terms of Chinalco's convertible bonds. "The strike price has significant value over the market price," he said.
"The coupon rate is comparable to the $US3.5 billion in debt that Rio just raised.
"The deal is worth very high value to Rio and is great contribution to the Australian economy. It relieves the pressure on a lot of Australian jobs and not only does it solve Rio's debt problem it enhances its ability to execute new opportunities."
In much of the debate in Australia "there has been a lack of understanding of the detail of this deal", Mr Wang said.
"It has been emotional rather than rational. You also have to understand that there has been plenty of criticism in China that we are paying too much. On net present value we are offering a very significant premium."
Mr Wang was also keen to hose down the perception that China's state-owned enterprises did not compete with each other.
"There is, and has been, fierce competition between different state-owned enterprises for domestic acquisitions and for acquisition in regional countries such as Vietnam, " he said.
"If we weren't involved in the deal with Rio we would have been interested in OZ Minerals, a situation we have been watching for a long time."
According to Mr Wang, people had also misunderstood the funding of the deal, which gave Chinalco interest rates up to 2 per cent (200 basis points) lower than major Australian corporations such as Telstra and Rio.
"Chinese banks are in a better position than those elsewhere in the world. Chinalco is seen by Chinese banks as blue-chip company," he said.
"The rate is comparable to borrowings that we have made in the past. It is comparable to bank loans by other companies with similar credit ratings. Most banks around the world are government backed in any case.
Mr Wang said Chinalco had made it very clear that as part of the deal it would back away from any pricing decisions. "Chinalco is not a customer of Rio's, we are a producer.
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