US copper futures jumped 3 percent Tuesday morning as renewed weakness in the dollar, firmer crude oil and general upbeat economic sentiment helped keep prices buoyed near 7-1/2-month highs.
Copper for July delivery firmed 6.35 cents, or 2.8 percent, to $2.3165 a lb by 10:13 am EDT (1413 GMT) on the New York Mercantile Exchange's COMEX division. Range from $2.26 to $2.3295. Last week, benchmark July copper climbed to its highest level since mid-October at $2.3530. COMEX estimated futures volume at 11,685 lots by 10 am.