US copper futures lost over one percent of their value on Thursday, after a surprise jump in US weekly jobless claims underscored recovery worries and investors squared positions ahead of Friday's monthly payrolls data. Copper for September delivery shed 5.10 cents, or 1.5 percent, to close at $3.3535 per lb on the COMEX metals division of the New York Mercantile Exchange.
Range from $3.3225 to $3.4085. On Wednesday, key September contract rallied to a three-month top at $3.4105. COMEX estimated copper futures volume at 37,539 lots by 1 pm EDT (1700 GMT). Final volume on Wednesday hit 41,050 lots. Open interest jumped 3,336 lots to 145,174 contracts open as of August 4.