BERLIN/BRUSSELS (Reuters) -Luxembourg’s former finance minister Pierre Gramegna will take over the euro zone’s bailout fund, the European Stability Mechanism (ESM), from December, succeeding Germany’s Klaus Regling who retired last month. “The ESM Board of Governors just appointed Pierre Gramegna by broad consensus to become the new ESM Managing Director as of 1 December,” the chairman of euro zone finance ministers Paschal Donohoe said in a Tweet. The ESM was created in 2012, during the euro zone’s sovereign debt crisis, to lend to euro zone governments cut off from markets. It has a 500 bill…