The incipient migration of clients from Credit Suisse to UBS should take about another 18 months, UBS CEO Sergio Ermotti said on Thursday, as his bank presses on with the integration of its former rival.

UBS acquired its longtime competitor last year after Credit Suisse collapsed due to a series of scandals and setbacks, and Ermotti has vowed to see through the integration.

Ermotti warned earlier this year that the IT integration of the two banks could take time, and addressed the shifting of customers onto the UBS system at an event in Washington, D.C.

"We are starting the migration of clients from the Credit Suisse platform into the UBS platform. This is going to go on for another 18 months or so," Ermotti said.

"It's very complex, but it's still something that I believe is going to add eventually greater value not only to shareholders, but also to clients and our own employees."

The integration would be a case study for regulators assessing the feasibility of the resolution of a systemically relevant bank, he said, arguing that UBS was in fact performing this task in the case of Credit Suisse.

(Reporting by Dave Graham; Editing by Richard Chang)