Southwest Airlines has narrowed its choice of a new reservations platform to “two players,” chief executive officer Gary Kelly said.

In announcing the acquisition of AirTran Airways at a price of $1.4 billion, Kelly said that Southwest is committed to expanding internationally, which will require a move to a new technology platform.

Kelly did not offer any hints as to the identity of the two vendors. However, sources close to the talks said Amadeus and Sabre are in the running.

Amadeus said that as a publicly traded company, it could not comment. Sabre also declined to comment.

Currently, AirTran uses Navitaire’s New Skies system. Southwest uses a customized system based on Braniff’s Cowboy system; the data has been hosted by Sabre since 1998.

“We have spent many months evaluating the systems,” Kelly said. Replacing a reservations system is “a 20-year decision, and you make these decisions very rarely,” he said.

In addition to enabling international service, a new reservations platform would improve revenue management and the ability to manage fare rules, he said. And a new platform will make the technology integration with AirTran easier, he added.

Integration cannot begin until the deal closes, Kelly said, and the regulatory approvals are likely to take months. The transaction also requires the approval of AirTran’s stockholders.

Once the deal closes, “nothing prevents a marketing integration before operational integration,” he said. But until the close, the two carriers do not plan to share codes.

After the integration, the carriers will operate under the Southwest name, logo and colors. Southwest’s frequent flyer program, due to be rolled out next year, will be all the more rewarding, Kelly said.