Wall Street would prefer just one strong leader at the helm of a new bank, with an equal number of executives from both sides beneath that person, in order to avoid indecision, ego clashes, disgruntled employees and bungled corporate strategy.

But many of the recent deals, particularly the merger between Citicorp and Travelers Group to form Citigroup and the combination of NationsBank and BankAmerica Corp have been marred by turmoil and power struggles at the top.Some say it indicates poor advance planning by the merging banks and can be a sign of deeper cultural dissension.

"Investors are deeply sceptical of any sort of significant power sharing agreement at the top, especially if the company is the product of a recent merger," David Hilder, an analyst at Morgan Stanley, said. "It'susually a sign the companies have not figured out how to truly integrate themselves, so they are using the Noah's Ark theory - two of everything."

The most recent example of shared power is the new Citigroup, whose "co-chief executives" - Travelers chairman Sandy Weill and Citicorp chairman John Reed - jointly lead and dictate the company's direction, analysts said.While analysts say it is too early to tell how Reed and Weill are getting along, they wonder how Citigroup can make decisions with two at the top and point to the resignation of company president Jamie Dimon as a bad omen of unrest to come.

Dimon, Weill's heir-apparent to run Citigroup, left amid complaints the integration of the corporate bank and Travelers' Salomon Smith Barney securities arm was moving too slowly.

Wall Street mourned him, briefly knocking Citigroup's stock price down because it saw the former head of Salomon Smith Barney as decisive, smart and a pivotal figure with the savvy needed to successfully bring Citicorp andTravelers together.

"There are few if any models of a successful investment/commercial bank on record," James Hanbury, an analyst at Schroders & Co said in November 3 report. "One of the reasons we thought this company could pull it off was managers like Dimon."

Dimon's exit has been seen as a sign of instability at the head of Citigroup and points to the trouble the US banks have had sticking together different corporate cultures.

Thomas Hanley, an analyst at Warburg Dillon Read said in a November 2 research report about Citigroup that "we are concerned that the company's management was not properly formed prior to the merger We have never seen co-CEOs successfully work on Wall Street and perhaps they never will."The recent merger of NationsBank and BankAmerica into the new BankAmerica Corp was also marred by a brief power struggle at the top that soon produced one casualty -- former BankAmerica chairman David Coulter.

Stephen Biggar, an analyst with S&P Equity Group said that "generally one persontends to succeed in terms of ultimately having power."

The view on Wall Street is that Coulter was ousted by Hugh McColl, head of merger partner NationsBank, after the new BankAmerica posted a sharp drop in third quarter profits in part because of large losses at Coulter's old company.

But while such a shake-up could be damaging to morale among old BankAmerica employees, analysts said it was still better to have a clear mandate from on high at a merged bank rather than forcing people to serve two masters for a long time.

McColl had also been chairman and chief executive of the new BankAmerica while Coulter was president, although Coulter was seen as a possible successor to the older McColl.