FRANKFURT, Germany (AP) _ The European Central Bank raised a key interest rate Thursday by a quarter percentage point, its sixth rate hike this year.

The move was largely unexpected after the 11-nation euro currency had shown signs of stability in recent weeks.

The announcement came after a meeting of the ECB's governing board, the officials who set interest rate policies for the 11 countries using the euro.

The quarter point rise in the refinancing rate to 4.75 percent follows a half-point increase on Aug. 31, when the central bank also surprised markets by raising the rate.

The refinancing rate is the interest the ECB charges commercial banks for buying back short-term securities when banks need cash.