Delta Air Lines and its partner Aeromexico have initiated a legal challenge against the U.S. Department of Transportation (DOT) to prevent the dissolution of their joint business partnership. The DOT has ordered the airlines to terminate their alliance, citing that Mexico's aviation policies are anti-competitive, particularly concerning airport slots in Mexico City, which violates the Open Skies agreement between the two countries. The carriers filed for a judicial review to maintain their antitrust immunity, which allows them to coordinate schedules and pricing for flights between the U.S. and Mexico. In their filing, the airlines stated that unwinding the joint venture would create significant operational and financial burdens and described the legal action as their only remaining option to protect their business interests.