The European Central Bank kept its key interest rate at 1.50 percent on Thursday, a spokesman said as markets waited keenly to see if the ECB would resume purchases of eurozone bonds. The ECB decision came as the head of the European Commission, Jose Manuel Barroso, urged European Union leaders to reinforce their financial defences and warned that debt contagion had now spread beyond the eurozone periphery. Central bank governors also kept two other benchmark rates, the marginal lending rate and the deposit rate, unchanged at 2.25 percent and 0.75 percent. A debt crisis that began in Greece before spreading to Ireland and Portugal now threatens to engulf the much bigger economies of Italy and Spain, leading Barroso to warn that \"it is clear that we are no longer managing a crisis just in the euro-area periphery.\"