Feb 16 (Reuters) - Copper prices advanced to their highest level in nearly nine years on Tuesday, boosted by optimism about a global economic recovery that bodes well for metal demand while supply is expected to remain tight. Benchmark copper on the London Metal Exchange rose as much as 0.5% to $8,437 a tonne in early Asian trading hours, rising for a third straight session to its highest since May 2012. The metal, often used as a gauge for global economic health, was up as much as 9.4% from its Feb. 2 low of $7,712 a tonne. A weak U.S. dollar also helped boost the appeal of greenback-priced copper. * Mainland Chinese markets will remain closed for the holidays until Wednesday, while Wall Street was shut on Monday. * For the top stories in metals and other news, click or * Asian shares advanced on Tuesday, putting world equities on course to extend their bull run for a 12th consecutive session as optimism about the global economic recovery and expectations of low interest rates drive investments into riskier assets. * The U.S. dollar was pinned down on Tuesday, as vaccine optimism boosted the British pound to an almost three-year high, while rising oil prices and buoyant expectations for global recovery supported commodity and trade-exposed currencies. DATA/EVENTS (GMT) 1000 Germany Zew Economic Sentiment Feb 1000 Germany Zew Current Conditions Feb 1000 EU GDP Flash Estimate QQ, YY Q4 PRICES Three month LME copper Most active ShFE copper Three month LME aluminium Most active ShFE aluminium Three month LME zinc Most active ShFE zinc Three month LME lead Most active ShFE lead Three month LME nickel Most active ShFE nickel Three month LME tin Most active ShFE tin ARBS (Reporting by Enrico Dela Cruz in Manila; Editing by Vinay Dwivedi)