Delta-Aeromexico Joint Venture Saved as Court Halts DOT Breakup

(MEXICO CITY INTERNATIONAL AIRPORT) Delta Air Lines and Aeromexico won an important reprieve this week when a federal appeals court put the brakes on the U.S. Department of Transportation’s order to unwind their cross‑border partnership. On November 12, 2025, the Eleventh Circuit granted an Eleventh Circuit stay that freezes the DOT breakup order, letting the Delta‑Aeromexico joint venture continue operating while the airlines challenge the decision. The stay arrives less than two months after the DOT issued a final order on September 15, 2025 directing the carriers to end their antitrust immunity and fully dismantle their joint business by January 1, 2026. For now, nothing changes for travelers shuttling between the United States 🇺🇸 and Mexico, but the legal fight will stretch well into next year.

What the DOT said and its proposed remedy

The DOT’s order, which the agency says followed a periodic review, concluded the joint venture had constrained competition—especially in Mexico City, where both airlines hold about 60% of takeoff and landing slots at the crowded hub. Officials cited Mexico’s tight slot allocation rules as a barrier to new entrants.

The department argued that ending antitrust immunity and forcing divestitures would open the U.S.–Mexico market to more carriers and lower fares. The proposed remedies included:

• Requiring Delta and Aeromexico to surrender 24 slot‑pairs at Mexico City International Airport (MEX)
• Requiring six slot‑pairs at New York’s JFK for use by low‑cost and other competing airlines

The goal: push more rivals into key city pairs and restore competitive pressure on fares.

The airlines’ response and immediate operational impact

Delta and Aeromexico fought back quickly. They argued the DOT’s analysis was flawed and that dismantling a nine‑year commercial framework would cause wide harm to passengers, employees, and regional economies.

They warned that an abrupt end could lead to:

• Flight cancellations
• Complex IT system changes
• Undermined network schedules built to function as a single platform

With the Eleventh Circuit stay in place, the joint venture can continue to:

• Coordinate routes, schedules, pricing, and capacity sharing
• Maintain frequent flyer reciprocity and codesharing
• Preserve mileage earning and redemption across both networks

That continuity is especially important with holiday and winter travel demand strong.

The stay does not decide who is right. The court paused the breakup order because the carriers showed that dismantling the partnership now would cause irreparable harm that could not be undone if they later win on appeal.

Timeline and what to expect from the appeals process

• The appeals process will include briefing, argument, and review of the DOT’s administrative record.
• According to filings, the freeze is expected to last until at least late summer 2026—protecting the alliance past the DOT’s original New Year’s Day deadline and through the peak summer season.
• The stay preserves operational certainty through winter and the busy summer scheduling season, where changes ripple through crew planning, aircraft rotations, and staffing.

Core legal and factual disputes

The dispute centers on several points:

• DOT’s claim: the U.S.–Mexico market has been closed to fresh competition at the top, notably at MEX, and the joint venture has not delivered promised connecting benefits beyond the largest hubs.
• DOT’s remedy: slot divestitures and removal of immunity to tilt the field toward low‑cost carriers.
• Airlines’ counter: the DOT ignored how the joint venture supports one‑stop options, banked connections, matched fares, and integrated customer support that benefit millions of passengers.

Key factual issues on appeal will include:

• Scope of DOT authority to revoke or condition antitrust immunity
• The factual record on slot access at MEX and JFK
• Whether benefits from the joint venture outweigh competitive harms at congested hubs

Why slot divestitures matter

Airport infrastructure can shape competition more than marketing agreements do. Mexico City’s main airport remains slot‑controlled under Mexican government rules often criticized by rivals seeking entry.

• The DOT wants 24 slot‑pairs at MEX and six at JFK to boost competitor access.
• Carriers say such divestitures could:
  • Force them to scale back off‑peak connectivity
  • Hollow out network effects that sustain smaller routes
  • Require complex schedule re‑engineering

Practical implications for travelers and businesses

For now, stability is the operative word. Immediate impacts:

• The Delta‑Aeromexico joint venture remains in effect.
• Joint schedules and pricing continue.
• Frequent flyer reciprocity and codeshares remain active.
• No slot transfers under the DOT plan will occur while the stay stands.
• Tickets already issued should remain valid as issued.

Business travel managers in cities like Atlanta, Detroit, New York, Monterrey, and Guadalajara reported relief that they do not need to rework first‑quarter travel policies. VisaVerge.com notes that corporate travel demand between the U.S. and Mexico recovered faster than many transborder markets after the pandemic, making network certainty valuable this winter.

Industry and policy implications

The case raises broader questions about regulatory reach and future alliance behavior:

• If courts narrow the DOT’s ability to revisit immunity, regulators may favor conditions at initial approvals instead of later revisions.
• If the DOT’s order survives, airlines might hesitate to deepen ties at capacity‑limited airports without more durable remedies.
• Airports with tight slots—Mexico City, New York, and others—remain flashpoints for debates about coordination versus competition.

Human and economic consequences

Beyond legal briefs, many stakeholders are affected:

• Cross‑border manufacturing clusters rely on predictable flights.
• Students and families depend on affordable, reliable links.
• Frontline staff can feel the strain from schedule and IT changes.
• The stay gives workers and travelers a measure of calm while the policy fight continues.

What could happen next

Possible outcomes after appeal:

1. Court upholds DOT:
   • The DOT’s breakup order revives.
   • Slot divestiture plans come back into play.
2. Court sides with airlines:
   • Alliance continues under immunity.
   • DOT may consider targeted remedies short of a breakup.

Either result will influence how regulators and airlines approach future partnerships at congested airports.

How to follow the case

Formal filings and public documents are the best sources:

• DOT posts final orders and materials publicly.
• Eleventh Circuit will post case entries as the appeal proceeds.
• Start tracking with official resources such as Regulations.gov.

Industry statements and investor updates will follow court milestones, but legal briefs will carry the central arguments. Businesses with large cross‑border travel budgets should monitor both the court calendar and potential notices about slot policy at MEX.

Bottom line

The Eleventh Circuit stay keeps the Delta‑Aeromexico joint venture alive well past the DOT’s January 1, 2026 deadline and turns a looming operational rupture into a prolonged courtroom battle. Travelers will continue to see aligned schedules, fares, and loyalty benefits through at least the coming summer. The DOT breakup order remains on the books—but it is frozen, awaiting a ruling that could reshape how regulators, airlines, and airports balance coordination and competition in crowded skies. In the meantime, passengers will likely hear the same familiar boarding calls—Delta and Aeromexico, code‑sharing and boarding together—while the legal process plays out.