Delta Air Lines and Aeromexico have won their legal challenge against a US Department of Transportation (DOT) order that would have forced the carriers to unwind their long-running transborder joint venture.
The US Court of Appeals for the Eleventh Circuit on August 20 vacated the DOT’s September 2025 decision to withdraw approval and antitrust immunity from the partnership. The court found the department’s action “arbitrary and capricious”, concluding that regulators had failed to explain why their review focused heavily on competitive conditions at Mexico City International Airport, rather than conducting the broader US-Mexico market analysis used when the tie-up was originally approved in 2016. It also questioned why the DOT applied an open-skies requirement that had not been imposed in comparable joint-venture cases involving Japan.
The immunised partnership allows Delta and Aeromexico to coordinate schedules, pricing and capacity and share revenues on services between the US and Mexico. Delta also holds a 20% stake in Aeromexico.
The DOT had moved to end the agreement after alleging that Mexican government policies had distorted competition. This included capacity reductions and slot changes at Mexico City, and the 2023 removal of all-cargo operations from the airport. Its order had required the carriers to end competitively sensitive cooperation by January 1, 2026, although that requirement was stayed while the appeal was heard.
The ruling means the joint venture and its antitrust immunity remain in force. In a statement, Delta said the partnership had delivered “greater choice, more seamless travel, and increased connectivity for consumers while supporting US jobs and economic growth.” Aeromexico added that it would continue providing a broader network and increased competition. The DOT said it is considering its legal options.
