In the annals of corporate governance, a tipping point of sorts came in April in, of all unlikely places, Charlotte, North Carolina. It was there, at the annual meeting of Bank of America’s shareholders, that investors voted by the narrowest of margins to strip chief executive Ken Lewis of his additional title of chairman of the board.

The vote, which was so close that the results were not announced until several hours after the meeting adjourned, was a stunning rebuke of Mr Lewis’ authority at the bank, amplified by shareholder anger at the way in which he conducted the acquisition of Merrill Lynch.