John Mack, the co-chief executive of Swiss-American banking group Credit Suisse and the head of Credit Suisse First Boston, its investment banking division, for just over three years, is to leave the group within weeks after the board said his contract was not being renewed.

Credit Suisse confirmed on Friday that Mack would be leaving without a pay-off after his contract expires on July 12. It declined to disclose details of his shareholding or share options in the bank or his pension arrangements.