* Nov exports down 2 pct y/y, imports down 5 pct y/y * Jan-Nov trade surplus more than doubles on the year * Euro zone southern periphery regains competitiveness By Martin Santa BRUSSELS, Jan 15 (Reuters) - The euro zone trade surplus widened in November because imports fell more sharply than exports, although shipments from the southern periphery rose in a sign that the bloc's worst-hit economies are regaining competitiveness. Exports from Spain, Portugal and Greece were up by 4 percent in the January to November period, compared to a year earlier, data from the EU's statistics office showed on Wednesday, and cumulative trade deficits shrank in all three year-on-year. That adds to signs that those countries that have struggled over the past few years to contain high debt levels via harsh austerity measures and to pull their economies out of recession are starting to improve. "It is encouraging that Spain, Portugal and Greece achieved export growth, which suggests that they are benefiting from improved competitiveness due to the reduced labour costs," Archer said. Exports from the euro zone as a whole fell by 2 percent on the year in November after a 1 percent rise in October, while imports dropped by 5 percent, following a 3 percent contraction in October. That resulted in an external trade surplus, unadjusted for seasonal swings, of 17.1 billion euros ($23.41 billion), in line with economists expectations. The surplus increased from a revised 16.8 billion euros in October. While exports overall fell back, the pick-up in the periphery coupled with euro zone industrial output data on Tuesday showing the fastest increase in November in nearly four years suggested the currency bloc was gaining momentum. "There are currently signs that euro zone recovery is gaining some traction and improving global growth over the coming months would really help matters by lifting euro zone exports and supporting business confidence," said Howard Archer, chief European economist at IHS. The United Kingdom remains the euro zone's main trading partner with cumulative exports for the January to November period up by 3 percent and imports down by 2 percent. Exports to China, the bloc's third-biggest trade partner after the second United States, were flat in the first 11 months of last year while imports fell 6 percent, leaving a 69 billion euro trade deficit. Germany's trade surplus rose in the first 11 months of the year, with flat exports and a 1 percent drop in imports, while France's deficit, shrinking year-on-year, was mainly due to a decline in imports. French President Francois Hollande outlined a new reform package on Tuesday to revive the euro zone's second-largest economy by cutting corporate taxes, labour costs and public spending.