GLENCORE posted a 13 percent increase in first-half copper output yesterday, in line with market forecasts and boosted by growth at its African and South American mines, but its zinc and nickel output dipped 11 percent and 8 percent, respectively. The London-listed company, which is due to report half-year results next week, makes almost half of its profit from copper and said its total output using feed from its own sources had risen to 741 000 tons in the first half of this year. Analysts had forecast 739 000 to 754 000 tons. The increase was mostly due to higher production at its Mutanda and Katanga mines in the Democratic Republic of Congo and its Antapaccay mine in Peru. Operational improvements at Collahuasi in Chile also helped. – Reuters