A Swiss regulatory filing https://www.ser-ag.com/en/resources/notifications-market-participants/management-transactions.html#/transaction-details/T1L5300075 this week showed an unidentified member of the bank's board of directors had made the purchase. A spokesman confirmed it was Horta-Osorio, who was approved by Credit Suisse shareholders as chairman on Friday.

The former Lloyds chief executive said last week he intends to look at the bank's risk management and culture in the wake of two major crises, as well as reviewing the bank's strategic options.

(Reporting by Michael Shields, editing by Louise Heavens)