UPDATE 2-Rio Tinto accepts Chinese offer for Kalahari

* Rio Tinto Rossing accepts CGNPC offer for Kalahari shares

* Rio says decision on Extract will be made "in due course"

LONDON/SYDNEY Jan 31 (Reuters) - Miner Rio Tinto has accepted China Guangdong Nuclear Power Corp's (CGNPC) bid for its shares in Kalahari Minerals, the major shareholder in one of the world's largest uranium projects, it said on Tuesday.

CGNPC, which is bidding alongside the China-Africa Development Fund in its effort to boost access to uranium supplies, wants to buy Kalahari for its 42.7 percent interest in Extract Resources, which owns the giant Husab uranium project in Namibia.

CGNPC has said it would make a subsequent offer for Extract if it won acceptances for at least 50 percent of Kalahari shares. It is under no obligation to extend the offer if it does not cross that threshold.

Rio had been expected to bow to the Chinese offer for Kalahari, which values the Namibia-focused miner at around $990 million. Hopes of a counter-offer faded, particularly after Rio made a bid for Canadian uranium prospector Hathor last year.

But it is unclear whether Rio, which owns the Rossing mine that neighbours Husab, will also tender its 14.2 percent stake in Extract in the event of a Chinese bid for those shares. Rio said in its statement that it would make a decision on whether to accept any offer for Extract "in due course".

Sources familiar with the matter said earlier that Rio was expected to agree to the Extract offer, but it was also considering folding some of its own maturing Namibian uranium assets into a joint venture with the Chinese company.

Husab is potentially the second-largest uranium mine in the world, and Rio Tinto has been in talks with Extract to combine its neighbouring Rossing mine, the world's longest-running open pit uranium mine, with Husab.

The deal comes as potential new sources of uranium supply are attracting interest, with the price of uranium miners battered last year after the Fukushima nuclear disaster.

Rio last year succeeded in a C$654 million takeover of Hathor after Cameco withdrew a rival offer.