NEW YORK (Reuters) - Bank of America Corp's <BAC.N> top Merrill Lynch brokerage boss, John Thiel, shook up the leadership ranks in a move that eliminated more than a half of the firm's regional manager jobs.

It also comes two weeks after BofA Chief Executive Brian Moynihan pushed out Thiel's former boss, Sallie Krawcheck, a move that fueled worries about the brokerage's direction as one part of a big commercial bank.

Moynihan is under pressure to slash spending and strengthen a bank facing enormous credit and legal costs stemming from the financial crisis.

The memo shows that Thiel is thinning to 11 from 24 the number of regional and division managers who oversee Merrill's more than 16,000 advisers and flattening the organization by scrapping four divisions.

Each region will have a market executive responsible for brokers and private bankers, consolidating what had been two parallel groups of managers, each reporting to Thiel.

Each region will have more flexibility in how they are run, to reflect the different needs of clients in various markets.

A Bank of America spokeswoman confirmed the memo.

On the heels of Krawcheck's departure, and growing worries Merrill will be more tightly governed by commercial bankers, Thiel's reorganization brings more upheaval to Merrill's brokers.

The other regional managers are Brett Bernard, mid East; Chris Dupuy, Pacific Northwest; Linda Houston, New England; Paul Lambert, mid America; Jeff Markham, Greater Texas; Don Plaus, south Atlantic; Jeff Ransdell, Southeast; Jodi Rolland, "heartland"; and Chandler Root, the southwest.

Sieg's brother, Andy, leads retirement services at Bank of America.

(Reporting by Joseph A. Giannone; Editing by Lincoln Feast)