A Federal Court Just Saved Delta and Aeromexico’s Joint Venture

On August 20, 2026, the US Court of Appeals for the Eleventh Circuit vacated a Department of Transportation order that had stripped Delta Air Lines and Aeromexico of the antitrust immunity underpinning their US-Mexico joint venture. The ruling keeps the two carriers’ coordinated pricing, scheduling and revenue-sharing arrangement intact after a year-long legal fight over how much competitive scrutiny the partnership deserves.

How the case got here

DOT approved the Delta-Aeromexico joint venture in 2016, granting antitrust immunity on the condition the carriers give up 24 slot pairs at Mexico City’s Benito Juarez International Airport and four at JFK to preserve competition.

The arrangement held for nearly a decade until Mexico moved to cut available slots at its capital’s airport and shifted cargo carriers to a second Mexico City field, a policy DOT said favored Aeromexico at US carriers’ expense.

That slot dispute is one piece of a broader US-Mexico aviation disagreement dating to 2022, when Mexico first capped capacity at its busiest airport for infrastructure and environmental reasons. US regulators argued the changes were applied unevenly and pushed American carriers toward less convenient schedules while Aeromexico kept its preferred slots.

Why the court sided with the airlines

The panel found DOT had departed from its own longstanding practice of evaluating an airline joint venture’s competitive effect across an entire route network. Instead, DOT narrowed its analysis to slot access at a single airport without adequately explaining the shift, which the court said made the order arbitrary and capricious.

The judges also found DOT had imposed an open-skies condition on the Delta-Aeromexico venture that it never applied to comparable joint ventures involving US and Japanese airlines. Treating a near-identical arrangement differently, without saying why, is exactly the kind of inconsistency that fails arbitrary-and-capricious review.

“We are not a rubber stamp,” the panel wrote. “Courts retain a role, and an important one, in ensuring that agencies have engaged in reasoned decisionmaking.”

Aeromexico said in a statement it is “reviewing the Court’s opinion and potential next steps with Delta and its legal advisors.” The airline added that the joint venture lets the two carriers keep offering “enhanced connectivity” and “increased competition” on US-Mexico routes.

The ruling lands as Delta keeps expanding its international network elsewhere, including a fourth Seattle long-haul route it recently added to challenge Alaska Airlines on transpacific service.