The department says if Sabre succeeds, it will lead to higher prices and less innovation for airlines and their customers. Sabre says it will challenge the lawsuit and is confident of winning. It says the companies offer complementary services.
Sabre is based in Southlake, Texas, and started as the reservations arm of American Airlines. It's the largest seller of services that let airlines sell flights through travel agents. Sabre had planned to close the deal Wednesday. It was announced in November.