The fighting between UBS AG investment-banking chief Carsten Kengeter and the deal makers who work for his division has led to the defection of two more top dealmakers.

Mary Ann Deignan, the head of the capital markets group for the America's, is departing UBS for Bank of America. And Gary Howe, co-head of the financial institutions group for the Americas, is also leaving the Swiss bank, according to a person familiar with the matter.

Because Deignan's departure is so sudden, the bank has no immediate replacement for Deignan, according to a different person at the bank who spoke on the condition of anonymity. Her responsibilities will be taken over by Tom Fox, the global head of capital markets to whom she had reported, according to UBS spokesperson Torrie von Alt. 

Howe's group will be led by Halle Benett, who has served as co-head since March of 2008, von Alt said.

Another top banker, Jimmy Neissa, co-head of global investment banking at UBS, is believed to be on the way out as well, according to a person close to the matter.

Top executives at UBS are negotiating to keep him at the bank, the person said.

Von-Alt denied Neissa was considering leaving in the strongest terms, saying she had just spoken with Neissa on the phone. Neissa did not return a call seeking comment.

UBS

UBS loading...

Quote  |  Chart  |  News  |  Profile

[UBS  Loading...      ()   ] has lost at least 50 dealmakers from its U.S. investment bank since 2009, raising questions about the leadership of its investment banking operation.

Troubles at the firm were recently reported in the Wall Street Journal, which said that Kengeter has held combative calls with senior bankers.

"He told us that bankers are spoiled children and we're the ones who messed this place up," one senior banker who recently left the firm told the Wall Street Journal. "You would get off the calls and think, 'how can I stay here any longer?'"

Pay levels at UBS’s investment bank are said to be lower than other Wall Street rivals. But many at the firm also say a growing disconnect between UBS headquarters in Zurich and the New York-based investment-banking unit is sapping morale.

And then there’s Kengeter himself.

Both departed bankers have supposedly said that Kengeter’s leadership was in part responsible for their departure.

“He’s @*&#-ing the place up,” one current UBS banker said.

Yesterday UBS AG said it hired Thomas Langford away from Morgan Stanley. He will be the new global head of the bank's energy investment banking division.

Bank of America Merrill Lynch

BAC loading...

Quote  |  Chart  |  News  |  Profile

[BAC  Loading...      ()   ] announced today that it has hired Deignan to head its Americas equity capital markets. CNBC hasn’t learned where Howe is going. Neither could be reached for comment.

___________________________________________

Questions? Comments? Email us at

Follow John on Twitter @ twitter.com/Carney

Follow NetNet on Twitter @ twitter.com/CNBCnetnet

Facebook us @ www.facebook.com/NetNetCNBC