Bank of America Merrill Lynch is suing three former wealth advisers in the US, who it claims used confidential information to lure its clients to a smaller boutique, as large banks battle to fend off competition from a wave of new start-ups and keep hold of their top staff and customers.

The Bank of America Merrill Lynch complaint alleges that the advisers violated their employment agreements by taking "confidential information of hundreds of Merrill Lynch accounts" worth $130m (€92.7m), and which generated $563,000 in commissions for the bank over the past year, according to Bloomberg.