Southwest Airlines Co. will use a travel-reservations system from Amadeus IT Group to operate international flights in 2014.
The contract could be expanded to Dallas-based Southwest's domestic network. Financial terms were not disclosed Thursday.
Southwest doesn't fly beyond the lower 48 states. But last year it bought AirTran, which flies to Mexico and the Caribbean, and plans to fold AirTran into the Southwest brand.
Southwest's current reservation system can't handle international operations.
Separately, Southwest CEO Gary Kelly said on a conference call with investors and reporters that his company will not change AirTran's policy of charging customers to check baggage, nor will it eliminate AirTran's first-class cabins.