Copper futures in New York traded down over 2 percent at the open on Tuesday amid some investor profit-taking as the market awaited new developments in the tense labour strife at Chile's Escondida mine, sources said.
By 10:20 am EDT (1420 GMT), copper for September delivery was down 8.25 cents, or 2.3 percent, at $3.4370 a lb on the New York Mercantile Exchange's COMEX division, near the bottom of its early $3.4365-$3.5295 trading band.
Floor dealers looked for near-term support at the $3.41 level, while overhead resistance continued to be eyed at the $3.77 high from July 12. December copper lost 6.45 cents at $3.4250, ranging between $3.4165 and $3.4950. Spot August slipped 8.25 cents to $3.44. COMEX copper volume at 9:00 am was estimated at 3,000 lots.