"He didn't see any long-term perspective at (Credit Suisse)any more," the source said of Khan's decision to leave Switzerland's second-biggest bank, announced late on Monday. "His relationship to (Chief Executive) Tidjane Thiam was professional, but not especially friendly, of late."

"His long-term goal is to attain a top job. But the path there could also lead through another division head job, it doesn't need to be a CEO role directly," he said, adding Khan planned to decide by late August or in September.

(Reporting by Oliver Hirt; writing by Brenna Hughes Neghaiwi; Editing by Michael Shields)

Stocks treated in this article : Credit Suisse Group AG, Julius Bär Gruppe, UBS Group