ITA has agreed to be acquired by Google, and antitrust regulators have been scrutinizing the deal.
Orbitz said it will continue to use ITA's QPX software, which manages airfare pricing and shopping. Several airlines also use QPX, including American, United, and Continental.
Orbitz said it would use the software for its Orbitz.com and CheapTickets.com websites. ITA is based in Cambridge, Mass.