John Mack has won enough supporters during his 15 months running Credit Suisse First Boston (CSFB) to secure half the top job at Credit Suisse Group after the departure of Lukas Mühlemann, chairman and chief executive of the company.

Mack will be co-chief executive with Oswald Gruebel, who was brought out of retirement in July to run insurance and private banking. Walter Kielholz, who runs Swiss Re, will become chairman of Credit Suisse, the bank said on Thursday. All three will retain responsibility for their individual business units.