Delta and Aeroméxico Contest US Decision on Joint Venture Termination

Delta Air Lines and Aeroméxico are seeking a judicial intervention to prevent the enforcement of a federal order that mandates the dissolution of their ongoing joint venture. They assert that this directive could disrupt cross-border travel and lead to significant financial losses.

In a legal filing submitted to the 11th Circuit Court of Appeals in Washington D.C., both airlines requested that judges halt the implementation of a September 2025 order from the U.S. Department of Transportation (DOT). This order calls for the termination of their nearly nine-year partnership, which was initially established after receiving regulatory approval.

The airlines argue that the DOT’s decision lacks justification and could adversely impact passengers, employees, and the communities that depend on their collaboration. Delta emphasized that the order would cause “severe disruptions” to its operations, stating that it has already canceled two flights on US-Mexico routes and may need to reduce more services by summer 2026 if the order is upheld. Aeroméxico noted that it would face the need to reallocate staff, hire new employees, and create separate IT systems to function independently, leading to what they termed “substantial, unrecoverable costs.”

This DOT ruling comes amid escalating tensions between the U.S. and Mexico regarding aviation policies. U.S. officials have voiced concerns over the slot allocation system at Benito Juárez International Airport (MEX), describing it as opaque and overly restrictive. They contend that interventions by the Mexican government have limited competition and disproportionately favored Aeroméxico and its U.S. partner.

The department’s order revoked the airlines’ antitrust immunity, which had allowed them to synchronize schedules, pricing, and capacity as if they were a singular entity for transborder flights. Regulators argue that their dominance at Mexico City, where they control approximately 60% of U.S.-bound flights, poses an “unacceptable” threat to consumer interests.

The order came after the Department of Justice supported the DOT’s stance, advocating for the joint venture’s discontinuation. U.S. officials pointed to a lack of transparency in Mexico’s airport operations, slot limitations that hinder rival airlines, and government actions, such as restricting cargo flights at Mexico City’s main airport.

Delta and Aeroméxico, both part of the SkyTeam alliance, established their joint cooperation agreement in 2016 with the blessing of U.S. and Mexican regulators. This partnership allowed them to share revenue and coordinate routes effectively. Additionally, Delta holds a 20% equity stake in Aeroméxico, valued at around $376 million.

The airlines maintain that the market remains competitive, noting that together they account for about 20% of available seats on U.S.-Mexico routes—comparable to American Airlines, which occupies a 21% market share. Delta believes that consumers benefit by as much as $800 million annually thanks to lower fares, new routes, and enhanced connections made possible through this collaboration.

This legal battle could potentially redefine the scope of U.S. regulatory power over international airline partnerships. If the DOT’s order is enforced, Delta and Aeroméxico will be required to separate their ticketing, marketing, and scheduling systems by early 2026, thus ending a partnership that has significantly influenced air travel between the U.S. and Mexico for nearly a decade.

The court’s filing comes after the DOT dismissed the airlines’ plea to postpone the order’s enforcement. The department has refrained from commenting on the legal appeal. A ruling from the 11th Circuit regarding the request for a stay is anticipated in the near future.