* Copper stocks at LME warehouses fall * Supply disruptions at copper mines * COMING UP: U.S. ISM non-manufacturing PMI, June; 1400 GMT (Updates price, adds comment) By Marie-Louise Gumuchian LONDON, July 6 (Reuters) - Copper fell on Wednesday after China raised interest rates and Moody's downgraded Portugal's credit rating over the euro zone's debt problems, but supply disruptions at some of the world's top copper mines are expected to keep a floor under prices. Three-month copper on the London Metal Exchange was at $9,460 a tonne by 1145 GMT, off a session low of $9,449.85, and from a close at $9,540 a tonne on Tuesday. It hit its highest since end-April on Tuesday at $9,565. China raised interest rates for the third time this year on Wednesday, making clear that taming inflation remains a top priority even as its vast economy gently eases. "The market did not react particularly well to it, but there was always scope for more tightening to come through in the second half," analyst Michael Widmer of Bank of America-Merrill Lynch said. "There were comments recently from Chinese policy makers about inflation being the key concern, so I'm not surprised really." Moody's became the first ratings agency to cut Portugal's credit standing to junk, warning the country may need a second round of rescue funds before it can return to capital markets. "The market wasn't expecting that ... People were still focused on Greece and hopes that gradually the situation was improving there," Nic Brown, head of commodity research at Natixis said. "It's clearly upset the market a little bit." The dollar was up against a basket of currencies. A stronger dollar makes commodities like metals more expensive for holders of other currencies. Traders also said Wednesday's options declaration day was pulling copper towards $9,500. Traders of calls and puts, the right to buy or sell a contract at a fixed price later, have to decide whether to exercise their options on the first Wednesday of each month during early LME trading hours. Prices were being supported by supply disruptions in Chile and Indonesia. An unusually severe winter storm has hit operations at Collahuasi, the world's No. 3 copper mine, with more heavy snow, wind and rain expected in Chile's copper-rich north. Workers at Codelco's El Teniente copper mine voted to ratify a company-wide, 24-hour strike for July 11 to protest the restructuring of the state mine. Union workers at all of Codelco's six copper mines plus a refinery district are expected to approve the call for strike from union leaders. Mining operations and production at Freeport-McMoRan Copper & Gold's Grasberg mine in Indonesia have also been significantly curtailed by the second day of a seven-day strike by about 8,000 workers, union workers said on Tuesday. FALLING COPPER STOCKS Investors will keep an eye on a raft of macroeconomic data and news this week with U.S. non-farm payrolls out on Friday and the European Central Bank's rate decision on Thursday. VTB Capital said it saw support for copper prices at $9,000 while resistance was at $9,700 a tonne for now. "The market could easily hit the top of the range should data surprise to the upside and the dollar take more losses," it said in a note. Investors were also keeping an eye out for indications of any monetary policy tightening from top copper consumer China. Stabilising prices remains the priority for the Chinese government even though price pressures have been contained, Premier Wen Jiabao said in comments published on Tuesday. Copper inventories at LME warehouses continued their downtrend, latest data showed. They last fell 1,225 tonnes to 461,275 tonnes. <0#LME-STOCKS> In other industry news, Australia's no. 2 nickel miner Minara Resources said it has placed production on standby a week after the acid plant at its ore processing facility was shut down, but added that it held enough inventory to cover sales commitments. Zambia's Munali nickel mine has resumed underground operations that were suspended in June due to ventilation problems, a company official said. Nickel traded at $23,284 a tonne from $23,300, but remained supported by declining inventories, which fell to their lowest since April 2009 at 105,480 tonnes. MNI-STOCKS Tin was at $26,450 from $26,250, after touching its highest in just over a month while zinc , used in galvanizing was at $2,388 from $2,411 a tonne. Battery material lead was at $2,679 from $2,695 a tonne. It earlier hit $2,701, its highest since mid-April. Aluminium was at $2,553 from $2,576 a tonne, having earlier hit a three-week high of $2,582.50. Metal Prices at 1144 GMT Comex copper in cents/lb, LME prices in $/T and SHFE prices in yuan/T Metal Last Change Pct Move End 2010 Ytd Pct move COMEX Cu 432.90 -1.30 -0.30 444.70 -2.65 LME Alum 0.00 -2576.00 -100.00 2470.00 -100.00 LME Cu 9455.00 -85.00 -0.89 9600.00 -1.51 LME Lead 2672.00 -23.00 -0.85 2550.00 4.78 LME Nickel 23225.00 -75.00 -0.32 24750.00 -6.16 LME Tin 26400.00 150.00 +0.57 26900.00 -1.86 LME Zinc 2383.00 -28.00 -1.16 2454.00 -2.89 SHFE Alu 17405.00 105.00 +0.61 16840.00 3.36 SHFE Cu* 70770.00 440.00 +0.63 71850.00 -1.50 SHFE Zin 18175.00 95.00 +0.53 19475.00 -6.68 ** 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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