The copper and gold miner OZ Minerals says it is expecting a drop in copper production this year.
The forecast comes after it recorded a fall in fourth quarter output.
OZ Minerals produced 23,000 tonnes of copper at its South Australian Prominent Hill mine in the period, down from almost 26,000 tonnes the previous quarter.
It says the mine's activity will peak this year and then start to decline, meaning less output.
Gold production also slipped in the quarter to 32,000 ounces from 35,000 in the September quarter.
The company's shares slumped 6 per cent to $6.87 by 10:48am (AEDT) on the report.
