By Chanyaporn Chanjaroen

May 16 (Bloomberg) -- Zinc rose in London, heading for the biggest weekly gain since February, as the biggest earthquake in nearly six decades in China hit output in the world's biggest producer. Aluminum also climbed.

China's 7.9-magnitude earthquake is affecting as much as 350,000 tons of zinc smelting capacity in Sichuan and neighboring provinces, according to Beijing Antaike Information Development Co. The tremor that took place May 12 also affected transportation and power supplies.

``If it's sustained damage, it's going to be a disruption that makes markets nervous,'' said Giles Lloyd, a zinc analyst at London-based researcher CRU in London.

Zinc rose $47, or 2 percent, to $2,365 a metric ton as of 4:45 p.m. on the London Metal Exchange. That's a 9.6 percent gain for the week, the biggest since the period ended Feb. 29.

Disrupted production in China will probably erode some of the global surplus estimated to be as much as 700,000 tons this year, Lloyd said. A labor strike at Anglo American Plc's Namibian Skorpion mine, Africa's largest zinc operation, is also hampering production, with the dispute entering a seventh day.

Skorpion, near Namibia's border with South Africa, has the capacity to produce about 150,000 tons of zinc a year. That's about 1 percent of global mine output forecast at 12.08 million tons this year by the International Lead and Zinc Study Group.

Sichuan Aostar Aluminum Co. and Sichuan Guangyuan Aluminum Co., with a combined capacity of 370,000 tons, face production curbs, the companies said, as transportation in the area was disrupted and there is a shortage of hydropower.

Smelter Problems

``Aluminum and zinc remain supported by Chinese smelter problems,'' said RBC Capital Markets' London-based traders Alex Heath and Randy North in an e-mailed report. ``Zinc remains one of the more vulnerable to the upside,'' they said.

Aluminum advanced $30 to $3,040 a ton.

Copper gained $139, or 1.7 percent, to $8,435 a ton. The metal is up 4.2 percent this week, after two weeks of losses.

Copper stockpiles earmarked for withdrawal from LME- registered warehouses have soared 84 percent in the past three days to 14,925 tons, accounting for 12 percent of total inventories. A Chilean group representing contract workers at Codelco threatened to resume a strike that affected 41 percent of the company's output last month.

``Every indicator of the copper market, particularly the supply side, is very bullish,'' Neil Buxton, managing director of London-based researcher GFMS Metals Ltd., said today by phone. ``Supply is tight and producers can't increase output at least in the near term.''

Copper Stocks

LME-tracked copper stockpiles added 375 tons, or 0.3 percent, to 121,225 tons, according to the exchange. Combined with those monitored by exchanges in New York and Shanghai, they totaled 182,493 tons, or 3.5 days of global demand, according to Bloomberg calculations. Last year's average was 4.9 days.

Chile's Confederation of Copper Workers may resume protests as workers haven't received bonuses outlined in the agreement that ended the original 20-day strike, Emilio Zarate, a leader of the confederation, said yesterday in a phone interview. Codelco shuttered three mines after the protest began April 16.

Tin fell $800, or 3.2 percent, to $24,500 a ton.

The rally in tin, the biggest on the LME this year, is near an end because Chinese producers will export more to take advantage of record prices, Galena Asset Management Ltd. said.

``It's not far off the finale,'' Alan Williamson, Galena's London-based chief economist, said yesterday by phone. Galena is the hedge-fund unit of closely held commodities trader Trafigura Beheer BV, based in Amsterdam. Its four funds manage a total of about $800 million.

Higher Exports

``Chinese exports will increase from now'' because international prices are higher than in the domestic market, Williamson said.

Tin for immediate delivery closed yesterday at $25,331 on the LME. In China, it's at about 159,000 yuan a ton ($22,742), including taxes, according to ITRI Ltd., a tin research company funded by producers.

Nickel increased $95 to $26,400 and lead climbed $71 to $2,347 a ton.

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