No-frills airline EasyJet says it has accepted in principle a £5.7bn takeover proposal from US firm Apollo Management, just days after accepting an offer from a rival suitor.

The Luton-based airline said Apollo’s bid delivered “a superior result” to investors than the previous offer from US investment firm Castlelake which EasyJet had also accepted in principle at the weekend.

EasyJet said Apollo’s offer was worth £7.15 per share, compared to Castlelake’s £6.90 per share proposal which it said it now “no longer cared” about accepting.

EasyJet is one of the largest airlines in Europe. It employs more than 19,000 people and operates around 1,200 routes in 35 European countries.

Analysts say EasyJet is an attractive target because it is profitable, has a large fleet of aircraft and also has a large number of aircraft on order.

It also has takeoff and landing slots at the main airports such as Gatwick and Paris Charles de Gaulle. The most popular slot machines can be worth tens of millions of pounds when traded between airlines.

EasyJet’s latest statement does not mean a deal has been confirmed. Apollo has been given a deadline of August 7 at 5pm to make a firm bid for EasyJet or withdraw. Castlelake’s deadline to make a firm offer is August 3.

Apollo’s decision came after Castlelake made a series of offers for EasyJet, which were initially rejected by the airline after accusing the US company of trying to buy it “on the cheap”.

However, on Sunday, EasyJet said it had reached an agreement in principle with Castlelake, a US investment firm, on a potential takeover bid worth around £5.2bn.

A major regulatory hurdle for any EasyJet acquisition is that European Union regulations stipulate that the airline must be majority owned by EU citizens.

Castlelake had proposed partnering with two EU citizens, businessmen Peter Bellew and Mark Breen. They would own an EU-based company that would have majority control of the airline.

EasyJet said Apollo’s offer represented an 81% increase on its share price of £3.94 on May 28, the last trading day before Castlelake’s takeover interest was made public.

Until EasyJet struck a deal with Castlelake, it had accused the US company of being “highly opportunistic” with its deals, arguing its share price had been “temporarily depressed”, partly due to the impact of the Iran war on the travel sector.