Delta Air Lines and Aeromexico have won an appeal against the US Department of Transportation's decision to terminate their transborder joint venture.

The ruling, reported by FlightGlobal, reverses the DOT's move to end the alliance between the two carriers, which governs their coordinated operations on routes between the United States and Mexico.

The dispute centers on the DOT's authority over the antitrust-immunized partnership. The Department had moved to terminate the joint venture, a step that would have unwound years of coordinated scheduling, pricing, and revenue-sharing arrangements between the US and Mexican carriers.

For the airlines, the appellate outcome preserves the commercial framework at the heart of their transborder strategy. Delta and Aeromexico had challenged the DOT's termination decision, arguing against the Department's basis for dissolving the arrangement.

The practical consequence for practitioners is significant. Aviation antitrust counsel will need to review the appellate court's reasoning closely, as it shapes the boundaries of the DOT's power to revoke immunization for international airline alliances. Carriers operating under similar joint ventures with antitrust immunity will be watching the decision as a check on unilateral regulatory termination, and any further proceedings on remand or reconsideration at the Department will determine the venture's long-term conditions.