Rio Tinto expects its copper production to fall by 15 per cent next year due to lower grades at its operations and a lack of growth until the Oyu Tolgoi project in Mongolia begins production in late 2012.

Rio expects to produce 661,000 tonnes of copper this year, which means its overall production will fall by about 100,000 tonnes next year – the equivalent of total production at a mid-size mine like OZ Min­erals’ Prominent Hill operation in South Australia. Total production next year will represent a fall of 18 per cent from production of 805,000 tonnes last year.