Anglo-Australian miner Rio Tinto Ltd., three months after a successful US$642 million ($A623 million) takeover bid for Canadian uranium miner Hathor Exploration Ltd. and its Roughrider uranium project, announced it has fully acquired complete ownership of the uranium company.

Rio Tinto Ltd. said on Thursday it had obtained the remaining 7.9 million shares not voluntarily offered after it made its takeover bid. The new development now makes Rio Tinto Ltd. the registered holder of 135.3 million, representing 100 per cent of the outstanding Hathor common shares.

In October, Rio Tinto Ltd. dislodged an earlier higher bid by rival Cameco Corp. of Canada when it agreed to pay C$578 million ($567 million) to acquire Hathor Exploration Ltd. In August, Cameco placed a bid of $C3.75 a share. It was eventually trumped by Rio Tinto Ltd. which made a bid at $C4.15 per share, 11 per cent higher than Cameco's.

Based near western Canada, Hathor Exploration Ltd.'s Athabasca Basin exploration properties in northern Saskatchewan include the 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. It supplies about a fifth of the world's uranium.

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

Rio Tinto Ltd., the world's fourth-largest uranium miner, has uranium mines in the Ranger mine in Australia through its 68 per cent interest in Energy Resources of Australia and the Rössing uranium mine in Namibia, in which it owns a 69 per cent 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.

Uranium is used to fuel nuclear power plants. Prices of uranium had been struggling to recover since the nuclear crisis hit Japan last March that led countries to re-evaluate their nuclear power programs.

Analysts and experts, however, forecast supply to recover in the immediate future driven by appetite from China and India as both Asian countries aim to boost domestic power capacities by using nuclear power.