In its quarterly report released today, OZ Minerals has dropped its production forecast for copper to between 70,000 and 75,000 tonnes for 2013 and left its gold production forecast unchanged at between 120,000 and 130,000 ounces. It said record tonnes were mined in the September quarter, but the required face advancement was not achieved, thus making output lower than expected. OZ Minerals said adjusting its forecasts would favour the long-term interests of the pit and ensure the most efficient and cost-effective operations. In August the group wrote down the value of its assets by $231 million after tax due to a slump in gold and copper prices. Shares in OZL are set to open lower this morning. (VIEW LINK)