SINGAPORE, Oct. 20 -- Copper rose to the highest level in almost six weeks in Shanghai as Peruvian miners began a nationwide strike and a walkout persisted at a BHP Billiton Ltd. mine in Chile, boosting concern supplies may be disrupted.
About 27,000 workers at a dozen mining companies in Peru, the third-largest copper producer, walked off their jobs yesterday, said Luis Castillo, the Mining Federation's general secretary. Miners want a bigger allocation of earnings after copper prices more than doubled this year.
"On one hand, stockpiles are accumulating," said Wu Pengfei, an analyst at Shanghai Liangmao Futures. "On the other hand, there are many risks to supply and the outlook is for demand to keep improving as well, so the bulls are winning."
Copper for January delivery on the Shanghai Futures Exchange rose as much as 1,340 yuan, or 2.7 percent from the previous settlement price, to 50,570 yuan ($7,408) a metric ton, the highest price since Sept. 9. The most active contract traded at 50,280 yuan at 10:56 a.m. local time.
Copper for delivery in three months on the London Metal Exchange was little changed at $6,466 a ton, after rising to $6,510 a ton yesterday, the highest price since Sept. 9. The December-delivery contract fell 0.5 percent to $2.9520 a pound on the Comex division of the New York Mercantile Exchange.
The strike at BHP Billiton's Spence copper mine in Chile had entered a seventh day, union spokesman Andres Ramirez said yesterday in an interview. Unionized workers at the site walked out on Oct. 13 after rejecting a wage offer.
Stockpiles of copper in Shanghai rose 12 percent to 100,217 tons last week, the highest level since Sept. 18 and nearly six times the amount at the start of the year, after the nation's imports jumped to a record in the first half of the year.
Still, demand in China, the world's largest metals user, will be able to "absorb" the excess metal, said Wu. An Oct. 22 report from the National Bureau of Statistics will probably show China's economic growth increased to 8.9 percent in the third quarter, according to a Bloomberg News survey of economists.
Among other LME-traded metals, aluminum, zinc and lead were little changed at $1,945 a ton, $2,108 a ton and $2,287 a ton respectively. Nickel slid 0.4 percent to $19,200 a ton, while tin hadn't traded.