Rio Tinto has more than doubled its half year net profit to $US4.4 billion ($A4.76 billion).

The world’s second largest miner’s profit was below consensus analyst expectations of $US4.57 billion.

The result was an improvement on a $US1.7 billion net profit in the first half of 2013.
Underlying earnings, which strips out $US843 million in one-off impairment charges, was up 21 per cent to $US5.1 billion ($A5.52 billion).

Chief executive Sam Walsh said the result was outstanding considering weaker commodity prices.

Iron ore earnings of $US4.7 billion dominated the result, but the biggest profit growth came in aluminium and copper, with 74 per cent and 71 per cent rises respectively.

Rio Tinto’s interim dividend of 96 US cents per share is up 15 per cent from a year ago, in line with expectations.