Southwest Airlines said it has connected the Southwest and AirTran Airways networks, enabling a single transaction for coordinated itineraries for flights from April 14.

Southwest and AirTran operate to a combined 97 destinations. The carriers were granted a single operating certificate by FAA last year, following Southwest’s acquisition of AirTran in 2011.

Southwest said in a statement that “full integration”—repainting and reconfiguring AirTran’s Boeing 737s, total airport facility commonality and using a single ticketing system—“is a large and complex process that is expected to be completed by the end of 2014.” So far, 30% of AirTran employees have officially switched over to Southwest, 11 AirTran 737-700s have been repainted and reconfigured, and there has been an ongoing conversion of AirTran-branded flights to Southwest-branded flights at airports.

According to Southwest, it realized $142 million of net, annualized, pre-tax merger synergies in 2012 and expects to achieve $400 million in such synergies in 2013. This excludes acquisition and integration expenses. 

AirTran president and Southwest chief commercial officer Bob Jordan said in a statement, “With a connected network, we can offer customers more itineraries, more destinations, more low fares, and a taste of what’s to come once the integration is complete.”