Greg Fleming, one of the architects of Merrill Lynch's sale to Bank of America, is leaving the firm just days after Merrill's brokerage chief Robert McCann also resigned from the US firm, according to media reports.

Mr Fleming's departure was revealed by a source who had seen an internal memo. 

The departure raises further question marks about the ability of Merrill Lynch to retain its top-performers in the group after the BoA takeover, which was completed a few days ago.

Mr Fleming, a former Merrill Lynch chief operating officer and president, did not respond immediately to a call or an email message, the news agency said. Television network CNBC reported that Yale University, where he earned his law degree, confirmed he was joining its faculty.

Mr Fleming was slated to head the global corporate and investment bank at BoA, reporting to ex-Merrill CEO John Thain, who is now president of the unit.

Mr McCann is to be replaced by his deputy, Dan Sontag, who has worked at Merrill Lynch for 30 years.