Three-month copper on the London Metal Exchange gained 0.2 percent to $8,245 a tonne by 0249 GMT, with volumes traded on LME Select at a thin 225 lots. Copper rose as high as $8,428.50 on Friday, its loftiest since last September, before trimming gains towards the close after data showed China's manufacturing sector was off to a sluggish start in 2012. China, the world's top copper user, is a key driver of the industrial metal, particularly at this time when demand elsewhere is shaky as the euro zone debt crisis persists. But concerns are rising that a slowing Chinese economy, which posted its weakest growth in 2-1/2 years in the last quarter of 2011, may cut Beijing's demand for copper after imports hit a record high 406,937 tonnes in December. With China and most in Asia closed, investors are waiting for a decision by euro zone finance ministers on the terms of a Greek debt restructuring they are ready to accept as part of a second bailout package for Athens after negotiators for private creditors said they could not improve their offer. A successful Greek agreement should help boost the euro, which is regaining some ground after early weakness in Asia, and along with it base metals prices. "However, one must not get too swept up in the upside euphoria, as markets are capable of turning on a dime given the still unresolved long-term debt situation in Europe and the fact that no one has a clear sense of just how much of a slowdown the Chinese are experiencing," INTL FCStone analyst Edward Meir said in a note. Supply constraints and falling LME inventories of copper have helped keep the metal's losses in check. Copper stockpiles monitored by the London Metal Exchange fell to their lowest since October 2009, data showed on Friday, highlighting dwindling supply in a market that some analysts expect to see in deficit this year. LME copper stocks dropped by 2,450 tonnes to 348,750 tonnes. But in China, copper inventories in warehouses overseen by the Shanghai Futures Exchange rose 9.3 percent, or 11,193 tonnes, to 131,645 tonnes last week, the highest since April 2011.