(Adds analyst comment, recasts) * IMF cuts global growth forecast to 4 pct from 4.3 pct * Technicals-LME copper to drop more to $8,190/T * COMING UP: FOMC meeting on spurring U.S. growth on Tuesday, Wednesday By Marie-Louise Gumuchian and Melanie Burton LONDON, Sept 20 (Reuters) - Copper fell to a new nine-month trough on Tuesday as concerns the global economic slowdown will crimp demand weighed on sentiment, compounded by an International Monetary Fund downgrade to global growth. Euro zone worries, a string of poor U.S. economic data, and the latest International Monetary Fund outlook have increasingly tempered expectations for copper demand. Three-month copper on the London Metal Exchange (LME) traded at $8,348 a tonne at 1420 GMT, down by 0.3 percent from Monday's close at $8,364. It earlier reached a new low since Nov. 30, 2010 at $8,308 a tonne. "Everything is about Europe - there's more and more nervousness about debt issues, and the potential downgrade of other European countries," said analyst David Wilson of Societe Generale. High debt loads, slowing output and market turmoil imperil economic recovery in Europe and prompt action by policymakers is essential to prevent the regional outlook from worsening, the IMF warned in its latest economic outlook on Tuesday. It also cut its forecast for global growth to 4.0 percent for this year and next, shaving projections for almost every region of the world and saying risks remained tilted to the downside. Just three months ago it had projected an expansion of 4.3 percent for 2011 and 4.5 percent for 2012. [ID;nW1E7JU006] The euro fell to a New York session low against the dollar as investors refocused on concerns about European debt contagion with Italy's debt rating cut earlier in the global session. Europe has come under increasing global pressure to resolve a crisis that has seen numerous ratings downgrades and financial rescues for Greece, Portugal and Ireland. Analysts said the crisis will have to be addressed by policymakers starting with the U.S. Fed meeting on Tuesday and Wednesday and the G20 and IMF/World Bank meetings this week. "U.S. housing starts data today were also worse than expected and that is not going to help," Wilson added. U.S. housing starts fell more than expected in August as groundbreaking for both single-family and multi-family units dropped, suggesting the economy will not get help from residential construction anytime soon. Analysts said that traders could be positioning for further signs of an accommodative monetary policy stance from the U.S. which finishes its rate meeting on Wednesday, although any impact on metals isn't expected to last. "Metal prices could... benefit from any further concerted actions on the part of key central banks, as was the case in the middle of the month," Commerzbank said in a note. "However, given the slowdown of the economic environment, we doubt the sustainability of a purely liquidity driven price rally." MINE STRIKES The appearance of an end to industrial action at two copper projects has also eroded copper price support, said analysts. More than a thousand workers returned to Freeport McMoRan Copper & Gold's strike-hit Indonesia mine on Monday, leading the union to say some production has restarted at the world's third-biggest copper mine. Workers at Peru's Cerro Verde mine, which yields 2 percent of the world's copper, agreed to end an indefinite strike they began last week, but may down tools again on Sept. 27, a union leader said Monday. "A partial end to a strike at Freeport McMoran's Grasberg copper and gold mine in Indonesia could also remove some of the support from copper, although the union said an agreement still has not been met," ANZ said in a note. "Sentiment has turned mostly bearish for this market." Lead stocks at LME warehouses, which have been rising since mid-August, hit their highest in more than 16 years as they jumped 15,250 tonnes to 345,425 tonnes and are now nearing records of 372,650 tonnes from Oct. 1994. MPB-STOCKS Although headline LME lead stocks are now close to record highs the absolute size of the lead market has also grown, with global consumption around 10 million tonnes a year, from around 6.5 million tonnes a year a decade or so ago, Standard Bank said in a research note. "As such, in terms of days' consumption, inventories are not quite as plentiful as the headline numbers suggest." Battery material lead traded at $2,316 from $2,301 a tonne. Zinc , used in galvanizing, traded at $2,097 from $2,100 a tonne. Aluminium changed hands at $2,338 a tonne, from $2,340 a tonne. Nickel traded at $21,042 a tonne from $21,000 while tin was seen at $22,799 from $22,710 a tonne. Tin premiums in Europe rose this week as declining inventories in LME warehouses and strong Chinese demand caused tightness in the market, traders said, with more gains eyed on expectations of further robust demand from China. Metal Prices at 1419 GMT Comex copper in cents/lb, LME prices in $/T and SHFE prices in yuan/T Metal Last Change Pct Move End 2009 Ytd Pct move COMEX Cu 375.00 -2.25 -0.60 334.65 12.06 LME Alum 0.00 -2340.00 -100.00 2230.00 -100.00 LME Cu 0.00 -8364.00 -100.00 7375.00 -100.00 LME Lead 2310.00 9.00 +0.39 2432.00 -5.02 LME Nickel 21175.00 175.00 +0.83 18525.00 14.30 LME Tin 23195.00 485.00 +2.14 16950.00 36.84 LME Zinc 2095.00 -5.00 -0.24 2560.00 -18.16 SHFE Alu 17055.00 95.00 +0.56 17160.00 -0.61 SHFE Cu* 62960.00 -410.00 -0.65 59900.00 5.11 SHFE Zin 16380.00 95.00 +0.58 21195.00 -22.72 ** 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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