FRANKFURT — The European Central Bank left its benchmark interest rate unchanged Thursday, amid signs that the euro zone economy could be slowly coming back to life.

The E.C.B. kept its main rate at a record low of 0.5 percent, as expected. Recent surveys of business sentiment have raised hopes that the euro zone economy could be emerging from recession. Any recovery will probably be weak, though, and insufficient to make a significant dent in euro zone unemployment that has remained at a record high of 12.1 percent for four months.  Read more