Rio Tinto, the world's second largest miner, today revealed a 51.8 per cent rise in profit for the first six months of the year due to soaring commodity prices as it reiterated its rejection of BHP Billiton's offer for the group.

However, shares in Rio Tinto fell 104p to £50.75 in early trading, joining other mining stocks whose prices fell on a decline in Chinese copper prices and renewed fears over world economic growth.

The company, which acquired Alcan, the aluminium producer, for $38 billion just over a year ago, announced that pre-tax profit for the six months to June 30 rose from $4.6 billion in the first half of last year to $9.6 billion.

Group revenue increased from $13.9 billion in the first half of 2007 to $30 billion this year.

Rio Tinto attributed its strong growth to high demand for commodities, in particular, from China. The company said that copper prices rose by 20 per cent during the period and it had negotiated record prices for iron ore with its major customers.

The effect of price movements for metals and minerals contributed $2.7 billion to a total $5.4 billion in underlying earnings.

Today's results are also the first to include a full six-month contribution from Alcan which, along with high demand for iron ore, increased underlying earnings by $616 million compared with last year.

Rio Tinto said that it is on course to deliver cost savings of $1.1 billion by the end of 2009, ahead of the initial estimate of $600 million.

Commenting on BHP Billiton's ongoing battle to secure control of Rio Tinto, chairman, Paul Skinner, said that its rival's offer was still being reviewed by the European competition authorities.

He said: "...the group's performance in the first half, together with our growth potential, supports the board's view that Rio Tinto presents a very strong standalone value proposition for shareholders."

He said: "While the equity markets are currently focused on downside risks, we believe there are potential offsets on the upside based on continued strength in commodity demand, low inventory levels and a supply side which continues to face multiple constraints.

“The group continues to perform strongly, and the outlook remains positive.”

Rio Tinto will pay shareholders a 31 per cent increase in the interim dividend to 68 cents. Shares in Rio Tinto rose 1.76p to £124.06 in early trading.

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