Bank of America is planning to defer bonus payments to some investment banking staff this year – a move certain to inflame tensions between its employees and officials of newly acquired Merrill Lynch, executives familiar with the matter say.

Andrew Cuomo, New York attorney-general, is investigating Merrill’s decision to accelerate the payment of nearly $4bn in bonuses – mostly in cash – to its employees, just days before the closing of its sale to BofA on January 1.