Court overturns DOT order to end Delta-Aeroméxico joint venture

The 11th US Circuit Court of Appeals has struck down a Department of Transportation order that had sought to dismantle the joint venture between Delta Air Lines and Aeroméxico. That venture coordinates schedules, fares and capacity on US-Mexico routes.

The court vacated the DOT's September 2025 order on August 20, 2026. It ruled that the department had failed to explain why it used a narrower method of analyzing competition than it had applied in earlier airline alliance cases. The joint venture had never actually been dismantled; the appeals court stayed the DOT's order in November 2025 while the legal challenge went forward.

The DOT's original 2016 approval of the partnership had examined competition across the full US-Mexico market, covering 1,687 city pairs, according to the ruling. Its 2025 review, by contrast, focused largely on conditions at Mexico City International Airport, which the court said accounts for roughly 21% of flights between the two countries.

The judges found that the department's final order lacked updated market-share data. It also did not assess how those shares might shift if the venture continued, and skipped a fresh review of individual city-pair markets. The court called this departure from the DOT's usual approach arbitrary and capricious, saying the department had not reasonably explained it.

The panel also questioned an open-skies condition the DOT had attached to the Delta-Aeroméxico arrangement. No similar requirement, the judges noted, had been imposed on comparable partnerships between US and Japanese carriers.

With the order vacated, Delta and Aeroméxico retain the antitrust immunity granted to their partnership in 2016, allowing them to keep coordinating on transborder flights between the two countries.