The United States Department of Transportation has confirmed its July 2025 order finding the joint venture of Aeroméxico (AM, México City International) and Delta Air Lines (DL, Atlanta Hartsfield Jackson) to be anticompetitive and terminated the approval and antitrust immunity granted to the partnership, effective January 1, 2026.

The regulator dismissed the airlines' pleadings, saying they had benefited from "an unfair advantage [...] and create unacceptable actual and potential harm for stakeholders, including consumers."

In order 2025-9-8, issued on September 15, 2025, the US regulator doubled down on its earlier claims that the Mexican government distorted the market by actions affecting slots at México City International, including banning all-cargo operations at the congested gateway, implementing a slot regime that allegedly does not meet international standards, and "upsetting" the market by what the DOT termed "arbitrary action". This was despite a recent decision to return some slots to US carriers.

"In such an environment, it is inappropriate for the Department to continue a grant of antitrust immunity because there is inadequate competition in the market. Significant problems become not just possible, but likely: higher fares in some markets, stifled innovation, reduced capacity (including frequencies and new routes), 'doing business' challenges for US carriers due to government intervention, and other impediments for incumbent competitors and new entrants," the DOT concluded.

The US regulator was not convinced by Delta's and Aeroméxico's comments opposing the termination of the JV, in which the airlines argued that their JV was beneficial to customers in both countries. However, the DOT opined that Aeroméxico and Delta are in a position to uniquely benefit from the actions of the Mexican government by, for example, shifting capacity between them, exacerbating rather than alleviating the effects of the disruptions.

The DOT pointed out that the two airlines could continue their commercial partnership in line with the current antitrust laws, and are well-positioned to benefit from such a cooperation thanks to Delta's 20% stake in Aeroméxico. The airlines' 2022 application for another antitrust immunity remains on hold, but not scrapped, and the DOT said that "if conditions change again, Delta and Aeroméxico will have the opportunity to refresh the record and seek to demonstrate that a new joint venture will meet statutory standards."

Aeroméxico said in a statement that it regretted "this decision, which ignores the benefits the alliance has provided to connectivity, tourism, and consumers in Mexico. [...] Aeroméxico and Delta are evaluating the order issued by the DOT to establish the alliance's next steps." The carrier underlined that the airlines' codeshare agreement and frequent flyer programmes reciprocity remain in place.

"We are disappointed that the Department of Transportation has chosen to terminate its approval of the strategic and pro-competitive partnership between Delta and Aeroméxico, a decision that will cause significant harm to US jobs, communities, and consumers travelling between the US and Mexico," Delta Air Lines said.