Rio Tinto Group, Australia's third largest mining firm, reported a lower iron ore production in the second quarter, a statement to the Australian Stock Exchange indicated.

In spite this report, the mining export giant still performed well on the S&P500/ASX200, shares rose 1.3 percent to A$67.41 in Sydney trading at 3:25 p.m. local time.

Output was 43.6 million metric tons, compared with 44.6 million tons a year earlier, the London-based company said today in a statement to the Australian stock exchange.

This is below analyst expectations: 44.8 million tons by UBS AG and Credit Suisse at 51.3 million tons for the quarter.

However, this did not affect presumptions that demand for the ore is higher than expected, driven by demand for steel in China and Brazil.

A related Bloomberg report showed that in 2009, sales of the iron ore constituted 28 percent or $12.6 of overall revenues.

Rio Tinto's chief executive officer Tom Albanese said in the statement: Markets for most of our products are strong and the overall long term demand outlook is positive."

"A slight slowdown in Chinese growth have led to some weakening in sentiment. We believe this pattern of volatility in the global economy is set to continue," he said.