Europe's policymakers warn against excessive optimism over ECB's bond buying

CERNOBBIO, Italy - (Reuters) - European policymakers warned on Saturday against excessive optimism following the launch of the European Central Bank's bond buying program, with Governing Council member Ignazio Visco saying interest rates could not remain near zero forever. The ECB began a program of buying sovereign bonds, or quantitative easing, on Monday with a view to supporting growth and lifting euro zone inflation towards its target of just under 2 percent. Visco, Italy's central banker, s