William J. Baer was confirmed by the Senate on Sunday as the government's top antitrust lawyer, placing him in charge of the Justice Department division that reviews corporate mergers and prosecutes price-fixing cases, the New York Times DealBook blog reported on Monday. The confirmation of Mr. Baer to serve as assistant attorney general for the antitrust division was widely expected, but had been stalled since September, when the Senate Judiciary Committee approved his nomination by a 12 to 5 vote. President Obama first nominated Baer last February.