Rio Tinto, which yesterday refused to rule out going to the equity markets to raise cash to help pay down its debts, was today the subject of speculation about cash injection talks with Chinalco.

The Times newspaper in the United Kingdom reported that sources close to the miner said it was in discussions with Chinalco, the Aluminium Corporation of China.

Rio is reportedly considering either selling Chinalco assets or a potential cash for equity deal.

The major miner wants to reduce its debts by $US10 billion by the end of the year, and has been trying to sell off assets to raise the necessary cash.

However, with commodity prices at five-year lows and credit markets still tight, sales have been slow.

Earlier this week the miner announced it had sold its 50% stake in the Alcan Ningxia aluminium project in China to joint venture partner Qingtongxia Aluminium Group Co for $US125 million.

Even before the global credit crisis hit, Rio's sales were slow going.

Last year, the miner flagged a $US10 billion sell-off that included offloading Rio Tinto Energy America, Rio Tinto Alcan Packaging, Rio Tinto Alcan Engineered Products and interests in the Northparkes copper mine and the Sweetwater uranium assets, as well as the company's talc and borates business.

Out of these planned divestments, Rio only managed to sell the Cortez gold mine for $1.7 billion, the Greens Creek silver project for $750 million, and the Kintyre uranium deposit for $495 million.

The bulk of Rio's $US42 billion in debt was taken on when the miner snapped up Canadian aluminium maker Alcan for $38.1 billion last year. In October this year, $8.9 billion of that debt matures.

Meanwhile, last month, the major miner said it would slash 14,000 jobs and cut 2009 net capital expenditure guidance by $5 billion.

Shares in Rio fell yesterday after the company said it could consider an equity placement to help bolster its position, and were down another 40c to $40.55 today.

Meanwhile, Xstrata has also come under scrutiny as it has reportedly signed up JP Morgan to manage a rights issue or share placement, according London's Daily Telegraph.

Other media have speculated Xstrata could be looking at raising $5 billion to help fund acquisitions or pay down its debt load of around $16 billion.

Media reports have suggested Xstrata may be seeking to sell off some assets to its part-owner, trading house Glencore International.

Shares in the Swiss miner fell by as much as 9% in London overnight on the speculation.