Copper prices recorded the largest gain in 11 months on Monday after a massive quake in Chile halted the production of four mines in the world's largest copper producer.

The May delivery gained 20.3 cents, or 6.2 percent, to US$3.4870 a pound at 10:05 AM Sydney time (0005 GMT) in after-hours electronic trading on the Comex division of the New York Mercantile Exchange, Bloomberg reported.

It was the largest intraday gain for the most-active futures since April last year.

Chile's state-run Codelco, the world's largest copper producer, was resuming production at its El Teniente mine, and the Andina mine is expected to restart operation quickly. The two mines produce 600,000 tons of copper annually.

The London-based Anglo American Plc mining company said on Sunday that power had been "partially" restored to its Los Bronces and El Soldado mines in Chile, which produce a combined 280,000 tons of copper a year.

The mines were closed Saturday because of power outages, the two companies said.

The four mines account for 16 percent of Chile's output. Chile, the world's largest copper supplier, makes up 36 percent of global exports of cooper, according to the international Copper Study Group.

The three-month copper contract that closed at US$7,195 a metric ton on the London Metal Exchange last week may rise to US$7,800 to US$8,000, up 11 percent, said David Threlkeld, president of the Resolved Inc.

A 8.8-magnitude quake rocked central Chile early Saturday, and has killed over more than 700 people and left hundreds of others missing. Chilean President Michelle Bachelet has declared a "state of catastrophe" in quake-hit areas.

(Xinhua News Agency March 1, 2010)