MARKETS-METALS (UPDATE 4) * U.S. third-quarter growth revised up to 2.6 percent * Collahuasi port accident fuels supply concerns * Coming Up: U.S. existing home sales, 1500 GMT. (Recasts, updates prices, adds detail/comment) By Silvia Antonioli and Michael Taylor LONDON, Dec 22 (Reuters) - Copper stayed within reach of record highs on Wednesday as the dollar weakened and supply concerns persisted, but investor book-squaring undermined prices of the industrial metal. At 1437 GMT, copper on the London Metal Exchange traded at $9,342 a tonne from a close at $9,365 on Tuesday. It earlier touched a high at $9,390.25. The metal, used in power and construction, touched a new record of $9,392 a tonne on Tuesday, and has gained about 26 percent since the beginning of the year. "The reason is partly because of the holiday season, and also copper is taking a little bit of a break after the high yesterday," said Jesper Dannesboe, senior commodity strategist at Societe Generale. "Yes, I would imagine (some book squaring) and volume is down, so it is natural," he added. "There will be a correction at some stage but we are quite bullish for next year." Industrial metals were little affected by data from the United States, the world's number one economy, which showed that economic growth was a touch higher than previously estimated in the third quarter, but below expectations. "That has been marginally negative for the markets ... it will take more bad news to trigger a big sell-off in base metals," added Dannesboe. Supply concerns remain a focus, after the world's No. 3 copper mine, Collahuasi, scrambled to find a new route for its exports after an accident shut its Patache port terminal. This was unlikely to affect the market in the short term but may have a big impact later on, according to market players. "We will see choppy movements in the next few days as people are taking their money off the table until the New Year," said Alex Heath, head of base metals at RBC Capital Markets. The U.S. dollar extended declines after the U.S. data. A weaker U.S. currency makes dollar-priced metals cheaper for non-U.S. investors. Expectations of Chinese buyers coming back into the market next year for restocking also boosted industrial metals' sentiment. TIGHTNESS Bolstering copper by stoking supply concerns, stocks of copper at LME warehouses have trended lower since February last year, when they hit 555,075 tonnes, their highest level since October 2003. However, stocks data has been less supportive recently, with inventories having trended higher since early December. They last rose 1,225 tonnes to 363,950 tonnes, their highest since early November. A dominant position controlling 80-90 percent of stock warrants on London Metal Exchange copper slipped to 50-80 percent, latest data showed. Investors concerned about market tightness have eyed a dominant position in copper since November. Worries about supplies in the near term have pushed the metal into a $50 a tonne backwardation -- premium for cash material over the three-month contract -- compared with a discount of $20 a tonne in late October. However, this backwardation has eased from $70 on Dec 13. Aluminium traded at $2,458 a tonne from $2,435 and zinc was at $2,324 from $2,328 a tonne. "Aluminium has been the busiest metal on the complex this morning, with the metal building on the sharp rally on Tuesday afternoon to trade back above $2,450 this morning with the move exacerbated by short covering," Standard Bank said in a note. Battery material lead was traded at $2,445 a tonne from $2,434 a tonne. On lead there was a backwardation of $9, reflecting a premium for cash lead over the three-month contract, the highest since April 2009 and versus a contango of $23 in early December. "It's a quite big upturn in lead at the minute, due to automotive and industrial activity," a trader said. There was a shortage in battery grade lead, which is of higher purity than LME material, he added, as European demand recovers after the economic downturn. Lead stocks in LME warehouses -- which have steadily risen since late 2008 -- last rose 300 tonnes to 207,800 tonnes. Tin traded at $26,675 a tonne from $26,890 a tonne, within reach of a record high of $27,500 a tonne hit on Nov. 10. Nickel was at $24,680 a tonne from $24,625 a tonne. Metal Prices at 1439 GMT Comex copper in cents/lb, LME prices in $/T and SHFE prices in yuan/T Metal Last Change Percent Move End 2009 Ytd Percent move COMEX Cu 426.50 -0.80 -0.19 334.65 27.45 LME Alum 2455.00 20.00 +0.82 2230.00 10.09 LME Cu 9358.50 157.50 +1.71 7375.00 26.89 LME Lead 2445.00 11.00 +0.45 2432.00 0.53 LME Nickel 24575.00 -50.00 -0.20 18525.00 32.66 LME Tin 26750.00 -140.00 -0.52 16950.00 57.82 LME Zinc 2317.50 -10.50 -0.45 2560.00 -9.47 SHFE Alu 16685.00 55.00 +0.33 17160.00 -2.77 SHFE Cu* 68700.00 -550.00 -0.79 59900.00 14.69 SHFE Zin 18760.00 -200.00 -1.05 21195.00 -11.49 ** Benchmark month for COMEX copper * 3rd contract month for SHFE AL, CU and ZN SHFE ZN began trading on 26/3/07

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