Copper hit three-week lows on Wednesday as worries about a prolonged US economic gloom made investors overlook the potential for supply shortages from a strike at Chile's giant Escondida mine. Prices of the industrial metal fell to their lowest levels since mid-July in both New York and London, closing more than 1 percent down on the day and about 3 percent off on the week.
US copper's most active futures contract, September, settled down 1.6 percent at $4.3260 a lb on the New York Mercantile Exchange's COMEX metals division copper. It earlier touched a 3-week low at $4.3205.