The United States Department of Justice has backed a Department of Transportation (DOT) proposal to revoke antitrust immunity for the joint venture between Delta Air Lines and Aeroméxico, arguing that the alliance may be impacting competitiveness.

In a filing, the DOJ stressed that immunity from US antitrust laws should be rare, granted only when genuine public benefits are realised and competition is preserved. “Competition is particularly valuable in the airline industry. It drives lower prices, better quality, and more of the services consumers want,” it said.

Last month, the DOT announced a series of measures to address Mexico’s disregard of the 2015 US-Mexico Air Transport Agreement, including its proposal to withdraw antitrust immunity for the joint venture.

The Department of Justice agreed that Mexican government actions such as operational limits at México City International, which forced US cargo carriers out of the airport and relocated them to México City Felipe Angeles, have undermined competitive conditions, restricting entry and expansion for some carriers.

“Because competitive open market access is critical to mitigate the potential loss in competition that may result from a grant of antitrust immunity to an international airline alliance, DOJ supports DOT’s tentative decision not to renew antitrust immunity for the JCA,” it said.

In a response to the DOT, Delta Air Lines said its joint venture “is unquestionably proconsumer, procompetitive, and pro-American,” generating nearly 4,000 jobs, more than USD310 million of the country’s GDP, and more than USD200 million in annual tourism spending.

If the cooperation agreement is unwound, those benefits will evaporate and the airlines’ competitors will capture the market, the two carriers argued, stating that up to two dozen routes could be cancelled, with smaller aircraft replacing large narrowbody jets on many other routes.

Delta said that instead of terminating the immunised joint venture, the DOT should continue taking other measures to address its concerns regarding Mexico’s compliance with the Air Transport Agreement and that punitive action should be targeted at Mexico’s government, not at a binational business venture.

The carrier commended the DOT for invoking Part 213 and Part 212 to impose scheduled filing and charter authorisation requirements on all Mexican carriers serving the United States and, if necessary, restrictions on their schedules.

“Delta encourages the Department to aggressively deploy these tools to achieve its policy goals and vindicate American interests, and to do so prior to undertaking any adverse action against the JCA, in order to allow sufficient time to evaluate their efficacy,” the airline said.

ch-aviation has reached out to Aeroméxico for comment. The carrier did not have a response available at this time.