Rio Tinto has posted a 35% rise in profit to $7.8bn during the first half of 2011 when compared with the same period last year.

The firm has also invested $5.1bn to develop its world-class tier-one assets, as part of its capital expenditure programme.

Cash flow from operations rose 31% from the same period last year to $12.9bn.

Rio Tinto has increased its investment in Ivanhoe to 46.5% and expects the first commercial production from Oyu Tolgoi copper-gold project in Mongolia by 2013.

The firm has also completed the total acquisition of Riversdale and expects first coal from the Benga project by the end of 2011.