A wealthy South American family has filed a $612m (€475.3m) countersuit against Merrill Lynch, alleging that it inappropriately liquidated a profitable account to cover separate losses incurred from the collapse of Bear Stearns, eight months after the US bank filed a suit to recover unpaid fees from the family.

In an answering memorandum to Merrill Lynch's amended complaint, filed in the Supreme Court of the State of New York earlier this week, Ezequiel Nasser, son Raymond Nasser, uncle Albert Nasser and others, said that through one of their brokerage accounts they purchased options in Bear Stearns on the written advice of Merrill Lynch analysts.