(Adds analyst comment, details; updates prices) MELBOURNE, April 12 (Reuters) - London zinc fell to a four-month low on Thursday, tracking the prices of other steel materials as construction demand in China got off to a slow start in the usually strong second quarter. Markets came under pressure on Thursday as the threat of imminent U.S. military action in Syria rattled investors and sent oil prices higher on concerns about potential disruptions to supply and distribution. "The metals seem to have slipped back into following the global equity markets and thus prices are lower today as Asian stocks lose ground," said Kingdom Futures in a report. "The markets will certainly be more nervous than usual as people watch out for the U.S. response to Syria."
* London Metal Exchange zinc slid 2.7 percent to $3,150 a tonne by 0637 GMT, having earlier touched a low of $3,122.50, its weakest since Dec. 12. Prices crashed through support at the 200-day moving average of $3,172 a tonne, triggering a rush in sales from funds, a trader said.
* SRB SALES?: Industry sources said that the drop in prices was fuelled by talk that China's State Reserve Bureau had been selling zinc stocks, although several traders dismissed the talk as having been around in the market for several weeks. "It's supposed to be 50,000 tonnes - that's not really enough to impact the market," one trader said. The SRB did not immediately reply to a faxed request for comment.
* LME copper fell 1.2 percent to $6,863 a tonne, reflecting a sour tone across metals amid broad risk-off sentiment in the markets. Shanghai Futures Exchange copper fell 1.4 percent to 50,400 yuan ($8,030) a tonne.
* STEEL DEMAND: Iron ore futures in China have been falling, with investors worried about slipping steel margins this year and leaner demand in the world's top consumer. A seasonal pickup in China's construction activity that usually comes in April and May has been off to a slow start, traders said.
* ZINC: Longer term, zinc prices are expected to remain buoyant after hitting their highest in a decade because of years of underinvestment, the founder and chairman of Vedanta Resources said on Wednesday.
* CHINA POLLUTION: The Chinese city of Xuzhou is carrying out environmental inspections targeting air pollution emissions at industrial plants, construction sites and in the transport sector that are expected to last for as long as six months.
* CME Group has also revoked approved status for registration of Russian firm Rusal's metal for delivery against its aluminium futures contracts, according to a notice on its website.
* RUSAL: Trader Glencore, a Rusal shareholder and customer, will declare force majeure on some aluminium supply, a source familiar with the matter said.
* COMING UP: Euro zone industrial production Feb at 0900 GMT PRICES 0642 GMT
Three month LME copper 6860.5 Most active ShFE copper 50400 Three month LME aluminium 2229.5 Most active ShFE aluminium 14310 Three month LME zinc 3152 Most active ShFE zinc 23635 Three month LME lead 2365.5 Most active ShFE lead 18515 Three month LME nickel 13760 Most active ShFE nickel 102040 Three month LME tin 20900 Most active ShFE tin 142730 LME/SHFE COPPER LMESHFCUc3 327.59 LME/SHFE ALUMINIUM LMESHFALc3 -1938.84 LME/SHFE ZINC LMESHFZNc3 109.8 LME/SHFE LEAD LMESHFPBc3 136.56 LME/SHFE NICKEL LMESHFNIc3 -395.09
($1 = 6.2762 Chinese yuan)
(Reporting by Melanie Burton; Editing by Tom Hogue and Biju Dwarakanath)