Citi chief information officer (CIO) Marty Lippert has left the bank to return to his native Canada "for personal reasons".

Lippert was hired by Citi last summer, with a brief to revamp the financial services giant's IT setup and lower costs. He previously worked at the Royal Bank of Canada, where he was vice chairman and group head of global technology and operations.

"Marty's appointment emphasises the importance we place on technology in driving enterprise transformation, and we'll look to him to be a key architect of that change," Citi's chief executive Vikram Pandit said at the time of his appointment.

Areas under the CIO's responsibility at Citi include infrastructure, shared services and IT risk as well as operations and technology strategy and planning.

The bank's chief administrative officer Don Callahan will take on Lippert's responsibilities until a replacement can be found.