US Court Blocks DOT’s Move to Unwind Delta-Aeroméxico Partnership

A federal appeals court has temporarily halted a directive from the US Department of Transportation (DOT) that required Delta Air Lines and Aeroméxico to dissolve their long-standing transborder joint venture. This decision provides both airlines with a temporary reprieve as they contest the DOT’s orders.

A panel of three judges from the US Court of Appeals for the Eleventh Circuit granted an emergency stay that permits the airlines to maintain their partnership while the case undergoes judicial review. This stay suspends the DOT’s September 2025 order, which mandated that the airlines dismantle their alliance by January 1, 2026.

Delta and Aeroméxico jointly sought this stay in late October 2025, arguing that the accelerated timeline for dissolving their venture would lead to considerable financial and operational challenges. They informed the court that the order would disrupt numerous routes, diminish connectivity in the US-Mexico market, and impose costs that would not be recoverable even if they eventually won the case.

The DOT’s initial move to retract the antitrust immunity granted in 2016 was based on claims of anticompetitive effects in the transborder aviation market. Regulators cited persistent slot and access issues at Mexico City International Airport as disadvantages for competing airlines, alleging that the Delta-Aeroméxico partnership held an unfair competitive edge.

In response, the airlines contested these assertions, stating they function within a slot-controlled framework governed by Mexican authorities. They also maintained that the DOT’s decision failed to account for significant market shifts post-pandemic. Additionally, they highlighted the consumer advantages of the alliance, such as improved schedules, coordinated connections, and shared loyalty rewards.

The Eleventh Circuit’s ruling, dated November 12, 2025, does not settle the dispute between the airlines and the DOT. Instead, it maintains the existing structure of the partnership until a comprehensive review is completed. This legal process could extend for several months, with the timing of a final decision still unclear.

Delta asserts that the joint venture bolsters its presence in essential leisure and business sectors, while Aeroméxico heavily relies on this partnership to enhance its network in the United States and stay competitive with other airlines that operate similar partnerships across the Atlantic and Pacific.

In the upcoming weeks, the DOT can respond to the petition, and the court may seek further input from both parties. While the stay marks an initial victory for the airlines, the future of the joint venture hinges on the eventual outcome of this broader legal challenge.

What are your thoughts on the potential impacts of this legal battle on transborder aviation?