The U.S. Department of Justice is gathering support for its suit to block the $3.8 billion merger of JetBlue Airways and Spirit Airlines. The attorney generals of California, Maryland, New Jersey, and North Carolina signed on to the antitrust regulator’s lawsuit on Friday, the DOJ said in a statement.

Massachusetts, New York, and Washington, D.C., were already parties in the suit that the DOJ filed in the U.S. District Court for the District of Massachusetts on March 7. Principal Deputy Assistant Attorney General Doha Mekki said Friday that the additional state support would help the regulator “protect the benefits of competition in the airline industry on behalf of their residents.”

A JetBlue plane taxis past the control tower at San Juan airport
A JetBlue plane at the airport in San Juan.

The merger of JetBlue and Spirit would create the fifth largest U.S. airline by passenger numbers, with a roughly 8 percent share of the domestic market.

Not every state opposes the combination. The attorney general of Florida backed the merger after securing a commitment from JetBlue, which would acquire Spirit, to add flights in the state, including to underserved destinations in Florida, like capital Tallahassee, and to Europe.

An out-of-court settlement between the DOJ and airlines remains a possibility. However, U.S. Attorney General Merrick Garland has said that the combined JetBlue-Spirit “still violates” antitrust law even if the former were to give up what is arguable its strongest bargaining chip, its alliance with American Airlines.

The DOJ’s suit is scheduled to go to trial in a Massachusetts courtroom on October 16.

Tags: airlines, jetblue airways, justice department, mergers and acquisitions, spirit airlines, spirit takeover