The new chairman of global miner Rio Tinto said he would meet major shareholders in London next month, and would be prepared to scrap a $19.5 billion tie-up with China's state-owned Chinalco if they looked certain to oppose it.

I would trust we are not going to put a proposal to shareholders if we think there is any chance of it actually being voted down, Jan du Plessis told reporters after the group's annual meeting in Sydney on Monday.

If shareholders vote down the deal we will certainly have a problem and we will certainly have to take other action, he said.

Major Rio investors have complained that the Chinalco deal favors one shareholder over others. Under the plan, the Chinese group would buy stakes in Rio's iron ore, copper and aluminum assets and spend $7.2 billion on convertible debt that could double its Rio stake to 18 percent.

But, ahead of a vote expected in July, some are starting to recognize the deal may be the best option to slash Rio's debt.

Rio needs to pay back nearly $20 billion over the next two years, roughly half the $38 billion it paid for aluminum maker Alcan in late 2007 at the height of a commodities boom that's since sharply reversed.

People are becoming educated about the prices (Chinalco is paying) and the repositioning of the company with less debt and growth options, said fund manager Tim Schroeders of Pengana Capital.

Du Plessis said he was committed to the Chinalco deal and fended off a barrage of speculation at the meeting that Rio was readying a Plan B in case it fell through.

Outgoing chairman Paul Skinner was forced to defend the board's decision to all but ignore a 3.4-for-one share offer from rival BHP Billiton last year against criticism by shareholders that Rio would be in better shape if it had accepted the offer. BHP subsequently pulled its offer, saying it was unwilling to shoulder Rio's debt load in a down market.

We now live in a world in a different state, he told shareholders. The Chinalco proposition is the best value proposition available to Rio Tinto today.

WEEKEND TALKS?

There was also media speculation that BHP had held informal talks with Rio over the weekend, though fund managers said this was not behind a fall in Rio's share price on Monday. BHP refused comment on the speculation cited by broadcaster CNBC.

They are always talking, but I wouldn't call the talks 'formal', an investment banker with direct knowledge of the Chinalco-Rio deal told Reuters.

For his part, du Plessis said he had not met his BHP counterpart, Don Argus, at least in the past 24 hours.

Any talks between Rio and BHP now would have to focus on specific assets, or possibly a rights offer, as UK takeover rules bar BHP from reviving a full takeover bid until November.

Du Plessis said no new rights plans were under consideration.

Rio's shares slid as much as 4.4 percent on Monday, but that followed a 54 percent gain over the past three months, nearly 8 times better than the broader market <.AXJO> as investors were encouraged the Chinalco deal would ease Rio's debt burden.

The investment hinges on approval from Australia's Foreign Investment Review Board as well as shareholders in both Rio's London and Australia listed arms.

The tie-up is the biggest and most complex of a string of Chinese investments in Australian mining companies and has set off alarm bells in Canberra.

Australian regulators last month blocked a $1.7 billion takeover of OZ Minerals by China's state-owned Minmetals because it involved a mine near a weapons-testing range. Another Chinese firm, Hunan Valin Iron and Steel, was only allowed to buy up to 17.5 percent of iron ore miner Fortescue Metals Group after promising it would go no further.

Rio CEO Tom Albanese also knocked back speculation that Rio might sell coal mines in Australia to raise cash, saying none were for sale.

(Additional reporting by Sonali Paul in MELBOURNE, Bruce Hextall and Mette Fraende in SYDNEY and Joseph Chaney in HONG KONG Editing by Mark Bendeich & Ian Geoghegan)

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