Raiffeisen said its chairman is stepping down immediately, after the CEO he oversaw for five years was arrested last week in an unprecedented criminal investigation.

Raiffeisen Chairman Johannes Rueegg-Stuerm will step down as chairman of Raiffeisen, effective immediately, the cooperatively-organized Swiss bank said in a statement on Thursday.

The exit of Rueeg-Stuerm, a tenured professor who oversaw the bank part-time, is meant to put daylight between the bank and the scandal surrounding Pieren Vincenz, its former long-standing CEO. Vincenz has been remanded in a Zurich jail since last week over allegations he acted in bad faith

«This is an important step in order to preserve the credibility of Raiffeisen in the long-term, given the most recent developments in connection with the criminal investigation against the former head of management Pierin Vincenz as well as the ongoing Finma investigation against Raiffeisen,» the bank said.

«Unemcumbered» Renewal

Rueegg-Stuerm, who is virtually unknown in banking circles despite having been chairman for the last seven years, said his departure means someone «unencumbered» can continue renewing Raiffeisen's board. He will be replaced temporarily by Pascal Gantenbein, another professor, who joined the bank's board last year.

The bank will also beef up by adding Rolf Walker, an EY partner and auditor, and Thomas Rauber, head of a Swiss investment firm and local politician, to its board.

Whether the exit of Rueegg-Stuerm and other changes will be sufficient considering the apparent breadth of the criminal investigation remains to be seen: Vincenz's erstwhile protege, Patrik Gisel, now runs Raiffeisen and was on the board Investnet, one of the firms being scrutinized by Swiss prosecutors.

«Unfortunate Combination»

Last week, Gisel said he would not step down as CEO of Raiffeisen. Vincenz has denied wrong-doing. He is is being investigated over allegations he enriched himself with personal investments in firms that Raiffeisen also bought stakes and, later, of representing both buyer (the bank) and seller (himself).

Raiffeisen's detractors have criticized the bank's board as too lax to rein in Vincenz, an ambitious and dynamic Swiss banker who ran Raiffeisen for 17 years. Until Thursday, Ruegg-Stuerm dismissed the criticism, though conceding that hiring Vincenz's wife as head of the bank's legal department was an «unfortunate combination».