Southwest Airlines is buying Orlando-based AirTran Holdings for $1.4 billion and plans to move AirTran's headquarters from Orlando International Airport to Dallas. Executives at AirTran's Orlando headquarters, where about 500 employees work, will move to Dallas, but the airlines say no decision has been made on AirTran's other Orlando employees. In addition to its headquarters, AirTran has a maintenance facility and a new $7-million operations building at OIA. The purchase of AirTran, which will take on the Southwest Airlines name, gives Southwest entry into 37 new cities and expands its presence in New York, Boston and Atlanta. Southwest also gains routes to Mexico and the Caribbean. Southwest plans to drop AirTran's baggage fees after the deal is completed, which is expected to be by the middle of next year.