Anglo-Australian miner Rio Tinto Ltd. has succeeded in its $654-million takeover bid for Canadian uranium miner Hathor Exploration and its Roughrider uranium project after rival bidder Canadian Cameco Corp. backed out of the bidding war.

Rio Tinto Ltd. said it will prolong its offer by 10 days up until 12 December to acquire all the remaining outstanding shares of Hathor Exploration for $C4.70 ($A4.51) cash. So far, some 94,950,089 Hathor Exploration common shares representing 70.21 per cent of the shares have been tendered.

Hathor Exploration's Athabasca Basin exploration properties in northern Saskatchewan include its flagship Roughrider deposit, which holds around 58 million pounds of uranium, including the potential to produce 5 million pounds more of the yellow metal a year.

Located 25 km of Cameco Corp.'s existing Rabbit Lake uranium mill, any developer of the deposit would likely face the potentially expensive choice of building their own mill or using Cameco Corp.'s facilities.

In an interview with Montreal Gazette, Guy Hebert, CEO of Canadian uranium player Strateco Resources, said he sees a joint venture is in the offing between Rio Tinto Ltd. and Cameco Corp. in order to process Hathor Exploration's future ore within Cameco Corp.'s underutilized facilities.

Rio Tinto Ltd., the world's fourth-largest uranium miner, has uranium mines in the Ranger mine in Australia through its 68% interest in Energy Resources of Australia and the Rössing uranium mine in Namibia, in which it owns a 69% stake. Rio Tinto Ltd.'s annual uranium production in 2010 was 6293 tU. It sought to gain a foothold in the Athabasca basin, where 20 per cent of the world's uranium is produced.

Athabasca basin's dominant miners include Cameco Corp., which produces about 16 per cent of the world's uranium, and French nuclear giant Areva.

Cameco Corp. was the world's highest-producing uranium miner in 2010, with total output of 8758 tU from its Canada, Kazakhstan and the USA operations.

Meanwhile, Rio Tinto Ltd. has completed the divestment of its Colowyo Mine to Western Fuels-Colorado LLC in a sale signed on September. The thermal coal mine is located in western Colorado.

The transaction is the completion of Rio Tinto Ltd.'s divestment of all US thermal coal mines previously held by its wholly-owned subsidiary, Rio Tinto Energy America Inc.

Rio Tinto Ltd. has completed more than 20 divestments with total gross proceeds in excess of US$11 billion since 2008.