MW-DB054_greece_20141209074543_ZHBanks and other financial institutions in Europe are stress-testing their internal systems and dusting off two-year-old contingency plans for the possibility Greece could leave the region’s monetary union after a key election later this month.  Among the firms running through drills are Citigroup Inc. C, -0.79% Goldman Sachs Group Inc. GS, -1.22% and brokerage ICAP PLC IAP, -2.12% according to people familiar with the matter. The firms’ plans include detailed checks on counterparties that could be significantly affected by a Greek exit, looking at credit exposures and testing how they would provide cross-border funding to local operations. Some firms are also preparing for the impact on payment systems and conducting trial runs of currency-trading platforms to see how they would cope with adding a new Greek currency or dealing with potential capital controls. More