Rio Tinto Ltd subsidiary Energy Resources of Australia Ltd (ERA) has tried to distance itself from the mining giant's promise to double uranium production by 2012, according to a report in the Sydney Morning Herald newspaper.

Yesterday, when Rio's uranium arm ERA reported a surge in its half-year net profit, Rio came out and said it planned to aggressively increase production at its Rossing uranium mine in Namibia.

But during an investor briefing, Rio's chief executive of energy and minerals Preston Chiaro said Rio had not committed to doubling production from ERA and Rossing, the paper reported.

Mr Chiaro said there were plans to double Rossing's production, but only within the prescribed time. "We are looking at opportunities beyond ERA and Rossing," he told the paper.

ERA's net profit after tax swelled to $38.9 million for the six-months to June 20, 2008, compared to $5.7 million for the same period in 2007, driven by booming global uranium prices.