US copper finished near the 3-1/2-month high on Monday, after several central banks indicated they would continue to stimulate a stumbling economic recovery, triggering some short-cover buying, but volume was thin with London markets closed, traders said.
Copper for September delivery finished 1.49 percent, or 5.0 cents, higher at $3.34130 per lb on the COMEX metals division of the New York Mercantile Exchange. Prices hit an early high of $3.4310, a level last seen in early May, up from a session low at $3.3790 per pound.
COMEX estimated final copper futures volume at 34,825 lots. Open interest jumped by 2,687 lots to 142,198 contracts as of August 27. Copper for December delivery settled with 4.50 cent, or 1.33 percent, gains at $3.4295 per lb on COMEX.