Mining group Rio Tinto on Monday attempted to bolster its defences against a proposed £64bn ($133bn) takeover by rival BHP Billiton (NYSE: BHP - News) , promising to sell up to $30bn of non-core assets and raise its dividend by 30 per cent.

Tom Albanese, Rio Tinto chief executive, avoided arguing against the logic of a tie-up with BHP, but said the proposal of three BHP shares for each Rio share was "a long, long way away" from what the board would accept. Mr Albanese said commodity prices would stay strong for the foreseeable future because of growing demand from China and India, and played down the impact of an economic slowdown in the US.

"Even if there was a US recession next year, and we are not convinced there will be, it would have a lesser effect on Chinese GDP than before," he said.

High commodity prices would benefit the whole mining sector, he said, but Rio was poised to outperform its rivals because of its strong pipeline of growth projects and a track record of building projects on time.

"It will be a tide that lifts all boats but you have to look at companies' capability to execute." Mr Albanese said Rio's decision to raise its dividend by 30 per cent in 2007 and by at least 20 per cent in 2008 and 2009 was a reflection of confidence in Rio's future growth.

The company upgraded its iron ore output target to 600m tonnes a year, including 420m tonnes a year from its mines in Western Australia, and unveiled a $2.4bn investment in the Mesa A and Brockman 4 iron ore projects in the region. Mr Albanese said that, as well as iron ore, Rio had "unrivalled" growth prospects in aluminium and copper, including the La Granja copper project in Peru, which was bought by Rio in 2005 for $22m.

To help pay for this year's $38bn takeover of Alcan (NYSE: AL - News) , the Canadian aluminium group, Rio said it would now sell at least $15bn worth of non-core assets compared with earlier estimates of $10bn. As well as Alcan's packaging and engineered products division, this could include Rio's stake in Cortez, a US gold business, Rio's talc unit, the Northparkes copper and gold mine in Australia and two non-operational uranium projects.

Mr Albanese added that the value of businesses sold could reach $30bn if the group received attractive offers. Rio Tinto's London-listed shares closed down 83p, or 1.6 per cent, at £52.32. BHP's proposal valued Rio at £46.23 a share on Monday.