Shares in OZ Minerals have dropped more than seven per cent after the miner warned it would produce less gold this year than previously expected.

The company has cut its production guidance for 2013 to between 120,000 ounces to 130,000 ounces of gold, from the previous range of 130,000 to 150,000 ounces.

The lower guidance is due to a landslip at the company’s Malu mine in South Australia, which hurt production during the June quarter.

OZ Minerals says the landslip reduced safe access to the mining area but the pit returned to normal operation in July.

The company has retained its guidance for copper production of between 82,000 to 88,000 tonnes, with most of the production to come in the second half of the year.

“As advised previously, production for the year is expected to be weighted to the second half,” it said in a statement.

The company is Australia’s third largest copper producer.

OZ Minerals shares fell 34 cents, or 7.33 per cent, to $4.30 during Thursday’s trading session.

It has been a difficult couple of years for the miner, who has seen its shares drop from a high of more than $16 in late 2010.