Copper ended down after hitting its lowest in a week on Tuesday as geopolitical tension added to concerns over Europe's debt crisis, driving investment money into safer-havens such as gold and the dollar. COMEX copper for December delivery shed 4.90 cents, or 1.3 percent, to settle at $3.7025, down over 9 percent from a more than two-year peak at $4.0835 on November 11.