Advisory group says BofA shareholders should vote down proposal to let CEO stay chairman

An advisory firm wants Bank of America's shareholders to strip Bank of America's CEO, Brian Moynihan, of his second title — chairman of the board.

Institutional Shareholder Services reportedly recommended on Friday that the bank's shareholders vote down a proposal from the board allowing Moynihan to keep both titles, arguing that the bank would benefit from having independent oversight.

It's the latest move to unravel the board's decision to award the chairman job to Moynihan last year and comes ahead of a vote on the issue at a shareholder meeting scheduled for Sept. 22. Another advisory firm, Glass Lewis, recommended a vote against the proposal last week.

Moynihan has been the Charlotte, North Carolina-based bank's CEO since January 2010.