JetBlue’s Alliance Loss Adds to DOJ Arsenal Against Spirit Deal

A judge’s ode to small competitors as he struck down the American Airlines-JetBlue alliance intimates the cloudy legal outlook JetBlue faces in its quest to acquire Spirit Airlines Inc.

Judge Leo T. Sorokin sided with the Justice Department’s antitrust division in ruling last week that the Northeast Alliance (NEA)—a joint venture by American Airlines Group Inc. and JetBlue Airways Corp. in the region—"substantially diminishes” airline competition and harms consumers.

Sorokin’s references to the competitive balance provided by smaller competitors—in this case, JetBlue—could be yet another weapon that the DOJ can flip and use in its effort to block JetBlue’s own ...