Market watchers are speculating that William McDonough‘s arrival at Merrill Lynch suggests that the investment bank is looking to expand its scope into commercial banking, Forbes Magazine reports. McDonough, tapped to be vice chairman and special adviser to E. Stanley O’Neal, ML’s chief executive, comes with a resume that includes 10 years as the head of the Federal Reserve Bank of New York and chairman of the Public Company Accounting Oversight Board. In his new position at Merrill Lynch, McDonough will advise senior management in a campaign to develop new business with governments and financial institutions, which may include commercial banks. Fueling the speculation is a rumor floating around earlier this month that Merrill Lynch had its eye on Cleveland’s National City.