The decision by Ken Lewis, Bank of America chief executive, to step down at the end of the year took most of the bank’s directors and top managers by surprise, but was almost inevitable given the avalanche of regulatory issues descending on him.

As a result, BofA’s board, which has been almost entirely reconstituted since shareholders voted in April to strip Mr Lewis of his title as chairman, was caught flat-footed, and now has to launch a search for his replacement.