The bank, owned by Spain's Sabadell, said it had recognised costs related to the IT outage of 176.4 million pounds, while the update itself cost 318 million pounds.

CEO Paul Pester, whose position was called into question by lawmakers following the outage, said: "We're making progress in resolving the service problems customers experienced following our IT migration, and we will continue to work tirelessly until we have put things right."

(Reporting by Emma Rumney, editing by Silvia Aloisi)