COPPER futures have closed lower on the London Metal Exchange, weighed down by a strengthening US dollar, but finding support in headlines that a mine strike in Peru has been confirmed. THE LME's three-month copper contract was down 0.2 per cent at $US6,640.00 a metric ton at Wednesday's PM kerb close --a two-week low. The red metal is a US dollar-denominated commodity. When the greenback gains, it makes copper more expensive for holders of other currencies to purchase. This leads to a drop in demand and a fall in price. A strike at the Antamina mine -- Peru's largest mine -- is expected to begin on November 10 and to continue indefinitely. "Antamina has a 370,000 tons per year production capacity" and "while not totally unexpected, (the strike) does help to provide some additional support to the market," said Standard Bank in a research note. Most other base metals closed lower. Aluminium closed down 0.1 per cent at $US2,059.00 a ton, zinc closed down 1.6 per cent at $US2,220.00 a ton, nickel closed up 0.3 per cent at $US15,320.00, lead closed down 0.6 per cent at $US1,994.50 a ton, and tin closed up 0.6 per cent at $US19,645.00 a ton.