The carrier said it had reached an agreement in principle after Castlelake tabled a fifth offer at £6.90 a share after weeks of rejections.
There was no comment on the future of easyJet’s 19,000 employees across its airline and holidays divisions.
EasyJet was founded in 1995 by Stelios Haji-Ioannou flying from London Luton Airport to Glasgow and Edinburgh in Scotland, taking on established carriers with its low fare no-frills model.
Haji‑Ioannou left the board in 2010 but remains the biggest investor with a roughly 15% stake along with his family
The company in March it warned of higher fares and fuel shortages due to the US-Israeli war on Iran and Lebanon.
Castlelake tabled its first £5.60-a-share offer on June 12 which was rejected before the fifth bid was accepted on Sunday.
Reporting by Frank Prenesti for Sharecast.com