JetBlue and Spirit Airlines announced they mutually agreed to terminate their merger agreement after a federal court blocked the planned deal earlier this year.

The Department of Justice sued the two airlines to block the proposed merger, winning in a federal district court in January, with the two airlines appealing the ruling shortly after. The two airlines cited the unlikelihood of the regulatory hurdles being overcome ahead of the merger agreement’s July 24 deadline as the key reason for the decision on Monday.