NEW YORK (

TheStreet

) -- In another sign of the death knell of

Merrill Lynch's

once thundering herd, the head of its brokerage force is leaving the firm after being passed over in

Bank of America's

(BAC) - Get Bank of America Corp Report

management shakeup.

Daniel Sontag, who has spent more than three decades with Merrill, is retiring after BofA hired former

Citigroup

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executive

Sallie Krawcheck as his boss. The news was first reported by the

Wall Street Journal

, and confirmed by the company a

TheStreet Recommends

Reuters

report.

His departure is just the latest in a months-long string of top executives and brokers leaving due to clashes with BofA's investment banking division, and intense scrutiny from lawmakers and the public. Some have defected to competing banks -- particularly those abroad, like

Deutsche Bank

(DB) - Get Deutsche Bank AG Report

or

UBS

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-- or have started up their own operations.

Sontag's departure is particularly bittersweet, because he is seen as representing the culture of Merrill Lynch, and was appointed to his current role when his predecessor, Bob McCann, became the first to step down after the BofA-Merrill deal was finalized. Sontag, 53, joined Merrill in 1978 and has held several leadership positions through the years in various parts of the country.

Sontag told senior Merrill executives that he was leaving the firm because his "whole heart" was no longer in the job, according to the

Journal

, which cited anonymous sources familiar with the call.

Still, as Krawcheck's appointment makes clear, despite a mass migration of Merrill's old guard, BofA has had little trouble replacing top talent with fresh hires. Over the past few months, the firm has named a head of energy, corporate and investment banking, as well as new commodities and equity strategists, and promoted several internal candidates to top executive positions.

--

Written by Laura Tara LaCapra in New York.