NEW YORK (CNNfn) -An executive shakeup at financial giant Citigroup has resulted in the resignation of President Jamie Dimon, the one-time protégé of group co-CEO Sanford "Sandy" Weill.
Dimon's decision to leave Citigroup comes as the group begins to restructure its ailing corporate banking businesses, the company said late Sunday.
Dimon, 42, had held a variety of positions during his 13-year career as Weill's right-hand man, most recently serving as president of Citigroup as well as chairman and co-CEO of Salomon Smith Barney, the group's brokerage arm.
"My years with Sandy Weill have been a unique learning experience for me," Dimon said in Citigroup's statement. "I know Citigroup is well-poised for growth, so this is a perfect time for me to leave and regenerate with some new opportunities."
He did not comment further on his immediate plans for the future.
Smith Barney hands reshuffled
Meanwhile, Citigroup -- created by the recent merger of Travelers Group and Citicorp -- said it will combine the operations of Salomon Smith Barney (SSB) with the former Citicorp corporate banking businesses.
SSB had suffered large trading losses in the recent round of global financial volatility, forcing the brokerage to post a $324.9 million loss in the third quarter and announce layoffs.
The SSB results led Citigroup's corporate services arm to a "very disappointing" quarter, group co-CEOs Weill and John Reed said Monday.
Hints of the impending shuffle were apparent as recently as Oct. 21, when Citigroup singled out SSB's retail operations as an example of group units whose disposition was "still being determined."
However, at that time Citigroup also paid special attention to SSB's asset management division, listing the unit -- which showed a $70.5 million profit -- in its results as a separate core business.
For the duration, company watchers expect the division to remain under the corporate banking umbrella.
Mike Carpenter and Victor Menezes will head the combined SSB-corporate banking operation as co-CEOs.
Menezes formerly served the company as Citicorp chief financial officer and as a manager of the bank's Asian and Latin American corporate banking and strategy. He will oversee Citigroup's global corporate services businesses, including the fragile emerging markets portfolio.
Carpenter, the former chairman of Travelers Life and Annuity, will head SSB's private client and investment banking businesses.
In early electronic trading, Citigroup stock (CCI) was down 1-5/16 at 45-3/4, virtually erasing Friday's gains.