In International Travel Arrangers, Inc. v. NWA, Inc. (8th Cir. 1993) 991 F.2d 1389, the plaintiff, an independent tour operator, sued an airline and its affiliated air carrier and tour operator for predatory pricing under the federal Sherman Antitrust Act (15 U.S.C. 1 et seq.) (Sherman Act). The plaintiff sought to create a below-cost pricing claim based upon a segment of the seats sold on commercial airline flights. The court rejected plaintiff's argument that a federal predatory pricing claim can be based on isolating a segment of ticket sales and ignoring the defendant's overall pricing structure. The court stated: "Even if some of Mainline's fares were below cost, International has failed to establish ... that 'defendants' overall price structure was predatory.' To evaluate Mainline's pricing structure fairly, it was necessary to consider not just its lowest prices, but all of its prices for the routes involved, for that is the only basis upon which the relationship between Mainline's charges and costs could be determined." ( International Travel, supra, 991 F.2d at p. 1396.)