Southwest Airlines on Thursday reported a $131 million fourth-quarter profit, besting its $116 million profit in the same quarter in 2009

. Southwest also reported a $459 million profit for the full year, following a $99 million profit in 2009. The average fare during the fourth quarter grew 9 percent year over year to $131.17, helping to lift revenue per available seat mile by nearly 9 percent. Southwest expects to close its acquisition of AirTran Airways in the second quarter of 2011, anticipating approvals by the U.S. Department of Justice and AirTran stockholders.