Shares in British low-cost carrier ‌easyJet jumped as much as 11.4% on Monday after the airline agreed in principle to a 5.5 billion-pound ($7.34-billion) takeover bid from Castlelake over the weekend, but investors worried the deal might struggle to secure approval.

EasyJet said on Sunday it was prepared ​to accept U.S. investment firm Castlelake's sweetened bid of 6.90 pounds a piece, potentially ending lengthy negotiations and reshaping Europe's aviation industry.

The bid was ​a nearly 24% premium to easyJet's close on Friday, and around the 7 pounds price some investors were reportedly holding ⁠out for after four previous Castlelake proposals were rejected.

EasyJet, which rose to as much as 6.22 pounds on Monday, was up ​9.7% at 6.12 pounds as of 07:48 a.m. GMT.

A shareholder who declined to be named noted that current levels indicated the market ​was pricing a more than 30% probability of the deal falling through.

Still, the stock has gained more than 50% since Castlelake's interest became public in late May.

The potential take-private deal, which also includes a partial equity alternative, comes when airlines are grappling with ​sharply higher fuel prices and margin pressure linked to the Iran conflict.

JPMorgan analysts raised concerns about how ​aviation-focused lender Castlelake and easyJet would meet European Union ownership requirements and agree on a structure, with founder and controlling shareholder Stelios ‌Haji-Ioannou's views ⁠also unclear.

EasyJet said on Sunday that Castlelake had agreed to a "best endeavours" commitment to obtain regulatory clearances.

Haji-Ioannou declined to comment on Monday.

Castlelake has previously said it would own 49% of the bidding vehicle with the remainder held by two EU nationals, former easyJet chief operating officer Peter Bellew, and senior industry executive Mark Breen.

EU ​regulations require airlines operating ​in the bloc to ⁠be majority-owned and controlled by EU nationals.

JPMorgan also noted that approval from shareholders was not guaranteed, with prospects of a counter-bid also open, or other carriers looking to ​buy parts of easyJet.

"While a decent premium to the lackluster trading of recent ​years, it still ⁠represents a deep discount to the share price of the late 2010s, a sign of how in need easyJet is for someone to take the controls and plot a more successful flight path," said Chris Beauchamp, chief ⁠market analyst ​at trading platform IG.

Castlelake must formalize its offer by Aug. ​3 or walk away under British takeover rules.