UPDATE 1-Peru copper output edges up in June, gold and zinc drop

(Adds production figures for first half of 2014, details on output from top miners) LIMA, Aug 6 (Reuters) - Peru's gold and zinc output dropped 20 percent while copper edged up 2.5 percent and silver rose 6.4 percent in June from the same month a year earlier, the energy and mines ministry said on Wednesday. In the first half of 2014, Peru's copper output rose 9.4 percent while gold dropped 16.2 percent from the same period a year earlier. The Chinese mining company Chinalco, which i