Minneapolis-based Castlelake said Monday that easyJet’s board rejected its third takeover offer, but the U.S. investment firm is pressing shareholders to consider the bid as it seeks to take the UK budget airline private.

Under the proposed deal, accepting shareholders would receive 625 pence per share in cash, a roughly 59% premium over easyJet’s closing price of 394.20 pence on May 28, according to Castlelake. The total offer values easyJet at approximately £4.74 billion ($6.27 billion).

Castlelake said it wants easyJet shareholders to evaluate the proposal before the June 26 regulatory deadline required under UK takeover rules to announce a firm intention to make an offer or walk away. The bid marks the third takeover proposal the U.S. firm has made in the past month.

EasyJet did not immediately respond to a request for comment Monday. The company previously described the timing of Castlelake’s approach as opportunistic, arguing that its share price was temporarily depressed because of the situation in the Middle East.

Castlelake disclosed earlier this month that it was in the early stages of considering a bid for easyJet, in which it already holds a 2.14% stake. The firm later said any proposal would be valued at no less than 403.23 pence per share, putting the entire company at £3.06 billion.

The takeover effort comes amid a turbulent period for the airline industry following the outbreak of war in the Middle East, which has pushed jet fuel prices higher, disrupted air routes and weighed on travel demand. EasyJet’s shares have been especially affected given its exposure to European routes that have seen reduced traffic due to the conflict.