Capping a week of scrutiny for Bank of America, New York Attorney General Andrew Cuomo took another swing on Wednesday at uncovering which of the bank's executives knew about large losses and bonus payouts at Merrill Lynch just before the two banks merged last year. In an unusual move that could herald closer examination of corporate boards, Cuomo issued subpoenas to five current and former directors of the bank as part of his ongoing inquiry into its hastily arranged takeover of Merrill, a person briefed on the investigation said. A second person briefed on the inquiry said the directors who had received subpoenas included members of the firm's audit committee, which was responsible for reviewing significant legal matters, including the takeover of Merrill. Both the individuals who had been briefed on the inquiry asked not to be identified because they had signed confidentiality agreements involving the matter. The subpoenaed board members include William Barnet III, a real estate executive and the mayor of Spartanburg, S.C.; John T. Collins, a venture capital investor based in Boston; Tommy R. Franks, the retired four-star Army general; Walter E. Massey, the former president of Morehouse College in Atlanta; and Thomas J. May, head of the Boston utility company NSTAR, this person said. Cuomo's office wants to know whether Bank of America's board knew of additional losses discovered at Merrill after the merger was signed, as well as billions of dollars in bonus payments made to Merrill executives before the deal closed. Based on earlier interviews with the bank's executives, investigators believe the bank's audit committee and other directors might have known about losses and bonus payments before shareholders voted to approve the deal in early December, this person said. It is rare for prosecutors to subpoena members of a company's board in a criminal case. Cuomo's action is an indication that board members may not be immune to charges in cases where executives they oversee are prosecuted, said Cornelius Hurley, a professor at the Boston University School of Law. 'I would be very concerned if I was a director of Bank of America,' Hurley said. 