Robert Greenhill, currently president of rival Morgan Stanley, will become chief executive of Smith Barney Shearson, the new firm that will incorporate the retail and money-management arms of Shearson Lehman Brothers, the American Express subsidiary.
Mr Greenhill replaces Frank Zarb, who was promoted to a new position as a group chief executive with Primerica.
The appointment of Mr Greenhill, an investment banker, surprised many on Wall Street who had assumed that Primerica's chief executive, Sandy Weill, saw Smith Barney Shearson as a retail brokerage first and foremost. 'Greenhill is no salesman or trading guy, he's a banker,' one Smith Barney executive said. 'Everyone thought Sandy was building a low-class retail shop but it now seems he's planning to turn this place into a Merrill Lynch.'
Smith Barney also expects between 1,000 and 1,200 redundancies as a result of the Shearson merger.
Merrill is America's largest brokerage and largest investment bank, leading Wall Street in underwriting and mergers.
Mr Greenhill's hiring represents something of a defeat for some of Mr Weill's long-time associates, including Mr Zarb and Smith Barney's vice-chairman Lewis Glucksman, both of whom worked with him at Shearson Lehman a decade ago when he ran the firm for American Express.