"Outflows have reduced very significantly and we are seeing money now coming back in different parts of the firm," he said.

Koerner also said he has "zero concerns" about conflicts of interest surrounding the Swiss bank's acquisition of former Credit Suisse board member Michael Klein's advisory firm.

Earlier this month it was reported the Swiss bank will value M. Klein & Company at a few hundred million dollars.

(Reporting by Noele Illien, Editing by Louise Heavens)