NEW YORK (AP) — JetBlue Airways warned Friday that it may end its bid to acquire low-cost carrier Spirit Airlines as soon as this weekend, sending Spirit shares tumbling.

A federal judge this month sided with the Justice Department and blocked JetBlue’s proposed $3.8 billion purchase of Spirit, though the airlines have filed their intention to appeal with a higher court.

JetBlue said Friday that it has told Spirit certain conditions of their deal might not be met by a deadline, which could lead JetBlue to terminate the deal as early as Sunday.

Shares of Spirit Airlines Inc. slumped 16% immediately after JetBlue disclosed its view of the potential merger in a regulatory filing.