DALLAS (March 19, 2013)—Dallas-based Southwest Airlines and AirTran are selling itineraries for flights on both airlines in a single purchase.

Southwest Airlines Co. said it has completed combining both reservations networks.

Southwest bought AirTran in 2011, but is still operating it as a separate airline.

The combined itineraries will be available on flights starting April 14 from both airlines' websites and call centers.

A passenger could, for example, buy a single ticket that would cover a Southwest flight that connects to an AirTran international flight.

The two began linking itineraries in a few markets in January. Southwest plans to eventually eliminate the AirTran brand and repaint all the planes in Southwest colors.