Credit Suisse First Boston has announced a management shakeup that will see Chief Executive John Mack step down next month after nearly three years with the investment-banking powerhouse.

Mack, 59, who is also co-CEO of parent company Credit Suisse Group, will not renew his contract, which expires July 12, the company said Thursday.

Oswald Grübel, currently CEO of Credit Suisse Financial Services and co-CEO of Credit Suisse Group with Mack, has been appointed sole CEO of Credit Suisse Group.

“On behalf of the board of directors I wish to express our appreciation for everything that John J. Mack has accomplished at CSFB and Credit Suisse Group,” said chairman Walter Kielholz. “He led a dramatic turnaround of CSFB – delivering a US$1.4 billion profit last year, enhancing its reputation by resolving major regulatory challenges and strengthening the franchise in key areas for future growth.”

Also effective July 13, Brady Dougan will assume responsibility for the operations of the investment banking and wealth and asset management arm of the Group and be named CEO of Credit Suisse First Boston. Dougan, who joined CSFB in 1990, has previously held a series of senior positions in the firm, most recently co-president of Institutional Securities. “CSFB ranks among the most respected global investment banking platforms,” Dougan said. “The changes announced today reflect the strong commitment of the Group to investment banking.”

Walter Berchtold has been named head of Private Banking and Corporate & Retail Banking and CEO of Credit Suisse.

With the management shakeup, the group will be structured along three business lines: investment banking and wealth and asset management under the name CSFB; financial services, including global private banking and corporate and retail banking in Switzerland, under the name Credit Suisse; and insurance under Winterthur. Dougan, Berchtold and Leonhard Fischer, CEO of Winterthur, will all report directly to Grübel.

The board said that the structural and management changes are designed to take advantage of the group’s improved business momentum and to strengthen integration of its global capabilities.

“At this point in time, we have no interest in pursuing a merger with another financial institution,” Kielholz said in a release. “Credit Suisse Group’s financial performance has improved significantly as a result of strong measures taken by management. Our goals now are to accelerate organic growth and strengthen the competitive positioning of our core banking businesses; further improve the profitability of Winterthur and explore all options for capturing the value of our insurance business for stakeholders; and, finally, to position the Group to play a leading role in the evolution of the global financial services industry.”