easyJet has signed a ten-year deal with London Luton which, the airline says, could see it more than double its number of passengers at the airport from four to nine million.
The carrier has 15 aircraft based at Luton with plans to increase its capacity by around 20 per cent over the next year.
The news comes just days after easyJet and Gatwick Airport announced a seven-year growth and service improvement deal.
The "substantial" Luton deal will enable the airline to double its size at that airport over the next decade and add a greater range of business destinations.
easyJet CEO Carolyn McCall said: "Their financial investment and long-term commitment to developing London Luton were a key factor in agreeing to this new deal and will help us deliver our plans...
"London Luton can make a real and immediate contribution to the need for more airport capacity in the south-east."
But, while the deal was last year approved by Luton Borough Council, the decision is currently being reviewed by Communities Secretary Eric Pickles.
McCall said the speed of easyJet's plans is part reliant on this government approval. She said the airport aims to increase capacity from ten million to 18 million passengers a year.
By the time the proposed work is complete in 2026, the airport will have 20 passenger screening lanes, nine luggage reclaim belts and increased retail and seating areas are being proposed to meet the potential rise in passenger numbers.
London Luton managing director Glyn Jones said: "easyJet is our largest airline partner, accounting for 45 per cent of all passengers using the airport. We see this as a real vote of confidence in London Luton airport and its future."
The deal will also see the creation of 2,500 new jobs at the airport and surrounding region.