NEW YORK (CNN/Money) - Credit Suisse Group said Thursday its co-CEO John Mack will leave the investment bank amid a management shakeup and corporate restructuring.

Credit Suisse Group named Oswald Grubel sole CEO and Brady Dougan head of its Credit Suisse First Boston unit.

John Mack is a Wall Street veteran, who became known for his penchant to cut costs, which earned him the nickname "Mack the Knife." He went to Credit Suisse after a power struggle at investment bank Morgan Stanley.

"[John Mack] led a dramatic turnaround at CSFB -- delivering a $1.4B profit last year, enhancing its reputation by resolving major regulatory challenges and strengthening the franchise in key areas for future growth," said Credit Suisse Group chairman Walter Kielholz in a statement.

In addition, the company said it will restructure with investment banking and wealth and asset management under Credit Suisse First Boston, retail and corporate banking under Credit Suisse and insurance under its Winterhur unit.

"At this point in time, we have no interest in pursuing a merger with another financial institution," Kielholz added.