NEW YORK (AP) — JetBlue Airways says it may end its attempt to buy low-cost carrier Spirit Airlines as soon as this weekend, sending Spirit shares tumbling.

Spirit says it sees no reason to terminate the deal. The airlines have said they plan to appeal a federal judge’s ruling blocking blocked JetBlue’s proposed $3.8 billion purchase of Spirit.

But on Friday, JetBlue said in a regulatory filing that it could pull the plug on the merger because certain conditions might not be met by a deadline that the airlines set in their 2022 agreement.

JetBlue says it could terminate the deal with Spirit as early as Sunday.