Ken Lewis, chief executive of Bank of America, has said he regrets losing some of the Merrill Lynch staff that left following January’s merger and has vowed to start building a bigger investment banking business in Asia, for which the combined group will seek out fresh talent.

Mike Mayo, banks analyst at Calyon Securities, the US broker dealer of CLSA Asia-Pacific Markets, hosted a conference call with Lewis and asked about the high number of staff departures since the Merrill acquisition and the clash in cultures between the two organisations.