[ by Melanie Gretchen ] The Justice Department has promoted an in-house trial lawyer to serve as acting head of the antitrust division.  Until the Senate approves the House's choice for a permanent replacement, trial lawyer Joseph Wayland will serve as the government's top antitrust lawyer, replacing current acting chief, Sharis Pozen, who will leave at the end of the month. Mr. Wayland, 55, joined the antitrust division in September 2010 from Simpson Thatcher & Bartlett, where he had worked for nearly 25 years.  During his time at the unit, he led the civil enforcement division, blocking AT&T's merger with T-Mobile and serving as the lead lawyer when the government successfully barred H&R Block from buying TaxAct. Antitrust Pulls From Private Practice. Mr. Wayland could serve as acting chief for some time, as confirmation hearings fall to the back burner in a presidential election year.  William Baer, a law partner at Arnold & Porter, is President Obama's choice for a permanent replacement.  The last permanent antitrust chief was Christine Varney, who left the Justice Department last summer to join Cravath Swaine & Moore as a partner. Besides his experience as a trial lawyer, Mr. Wayland served as a captain in the U.S. Air Force, following graduation from Columbia Law.  "Joe's leadership and litigation expertise has made him a significant asset to the Antitrust Division and to the department. I know that he will maintain strong antitrust enforcement during this time of transition." -- Eric Holder, Jr., U.S. attorney general.   For further details, go to [Dealbook, 4/5/12].