Seven bankers from Morgan Stanley's wealth management unit resigned last month just weeks before Philip Purcell, chief executive, claimed morale at the division was solid. They leave a unit of which Purcell would remain in control under plans to split the firm in two.

Tarek Mooro, Fredrik Plyhr, Eran Ben-Zour, Andrea Brignone, Carlo Michienzi, Matteo Pusineri and Randol Curtis, all of whom are London-based private bankers, resigned last month.