Copper dropped for a third consecutive session in London after stockpiles rose and Japanese shipments of cable and wire fell, renewing concern that Asian demand may be slowing. Nickel and zinc declined.

Inventories of copper monitored by the London Metal Exchange rose 1,200 metric ton to 119,025 tons, the bourse said today in a daily report, bringing this month’s gain to 7.1 percent. Metal-wire and cable shipments in Japan, the world’s second-largest economy, fell 2.5 percent on year in May, according to preliminary data from the Japanese Electric Wire and Cable Makers’ Association.

“Demand is still fairly weak,” said David Thurtell, a London-based analyst at BNP Paribas, an LME member. He forecast the metal will drop to around $6,500 a ton in the second half.

Copper for delivery in three months on the LME fell $105, or 1.4 percent, to $7,330 a ton as of 10:26 a.m. local time. It lost 0.9 percent last week.

The metal, used in pipes and wiring, has dropped 2.6 percent in the past three sessions on signs of weakening demand from China. The country’s purchases of refined copper and alloy dropped to 121,383 tons in May, down 37 percent from April, according to revised figures issued last week by the Beijing- based customs office.

On June 23, workers at Southern Copper Corp., the world’s fifth-largest producer, began a strike for higher wages, according to smelter union general secretary Arnaldo Oviedo. At Dona Ines de Collahuasi, Chile’s third-largest copper mine, workers temporarily blocked a road to the site with burning tires in a protest for higher wages, although the action didn’t affect production at the mine, a union leader said on June 22.

Blockade Threat

Not all threats to production from labor unions have materialized. Workers at the Radomiro Tomic copper mine of Chilean company Codelco, the world’s largest producer of the metal, accepted a proposal on June 22 that included a wage increase of 3.7 percent above inflation, said Arturo Cruz, director of the Mining Union. On June 15, the union threatened to blockade two Codelco mines to press for their demands.

Chile’s Confederation of Copper Workers has yet to start a walkout over demands for higher wages for Codelco contractors. It earlier said the protest would begin as early as June 21.

Nickel fell $150 to $37,500 a ton. Nickel stockpiles tracked by the LME dropped 5.3 percent to 8,550 tons, the exchange said today in a daily report. That’s the biggest decline since April 17.

Among other metals traded on the LME, aluminum dropped $12 to $2,685 and zinc lost $95 to $3,455. Lead increased $10 to $2,550. Tin was unchanged at $13,825.

To contact the reporters on this story: Chanyaporn Chanjaroen in London at cchanjaroen@bloomberg.net ;

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