WASHINGTON -- A bipartisan group of U.S. House lawmakers is asking President Barack Obama for an investigation of the Federal Reserve, ratcheting up the pressure on the central bank coming from Capitol Hill.

Three Democrats and 14 Republicans wrote in the letter to Obama that the Fed shouldn't be granted any new authority amid questions about its role in fostering Bank of America Corp.'s acquisition of Merrill Lynch & Co. The White House's regulatory reform proposal would give the Fed broad new authority to contain systemic...