UPDATE 1-Rio Tinto gets strong support for rights offer

* Strong support for Rio Tinto's rights offer

* Chinalco takes up full entitlement to offer

* Still waiting for results of Rio Tinto's Australian issue (Adds Chinalco comments, details)

SYDNEY, July 2 - Global miner Rio Tinto <RIO.AX> <RIO.L> has pulled off one of the world's biggest rights issues, revealing on Thursday that shareholders had stumped up for almost all of its London shares on offer under the $15.2 billion issue.

The indebted Anglo-American firm, listed in both London and Australia, said it had acceptances for 96.97 percent of the new London stock, raising around 7.1 billion pounds ($11.66 billion), with the results of the Australian offer still to be released.

Its major shareholder, China's state-owned Chinalco [ALUMI.UL], later said it had taken up its full entitlement to the offer, which ranks as the fifth-biggest on record. It was a sign that Chinalco was far from severing ties with Rio Tinto.

Relations soured early last month after the miner called off a bigger equity partnership that would have seen the Chinese firm invest another $19.5 billion into dual-listed Rio Tinto.

Instead, Rio Tinto ditched the deal in favour of the rights issue and an iron ore joint venture with rival BHP Billiton <BHP.AX> <BLT.L>, raising howls of protest from China where state media characterised Rio as a "dishonourable woman".

Rio is raising money to cut a $38 billion debt mountain it accumulated when it bought Canadian aluminium group Alcan at the top of the commodities market in 2007.

Rio Tinto offered 21 new shares for every 40 held, priced at a steep discount of A$28.29 per Australian-listed share and 14 pounds per London-listed share.

The existing shares last traded in London at 21.55 pounds and in Australia at A$51.60.

Chinalco owns about 9 percent of the combined Rio Tinto group and would have spent $1.5 billion to take up all its rights, but it would have brought down its average holding cost in Rio Tinto to around 44 pounds per share.

Chinalco bought its initial stake at 60 pounds ($99.69) in February 2008, near the top of the market, in a raid on the London-listed stock. ($1=A$1.25) ($1=.6091 Sterling)