Plans to increase capacity at Luton Airport will be submitted this autumn after its owner and operator formally agreed to work together.
A contract between owner Luton Borough Council and operator London Luton Airport Operations Limited (LLAOL) has confirmed their relationship to 2031.
It follows a decision to integrate their individual expansion plans.
Earlier this year, the council said it could end its deal with LLAOL after the operator submitted a rival plan.
The combined proposal will allow for a maximum of 18 million passengers per year, creating about 4,750 jobs.
Any increase in capacity will take place within the existing boundary and use the existing runway.
London Luton Airport, the UK's fifth biggest, currently handles about 10 million passengers a year and is owned by the council under the name London Luton Airport Limited (LLAL).
In January, the council revealed proposals to boost passenger numbers to 18 million per year, but in March, LLAOL said 15 million was more realistic.
LLAL said they needed a partner to help cover the cost and there was a possibility they might end the current deal with LLAOL in 2014, when it was due to expire in 2028.
However, in June the two sides agreed to merge the plans in order to move forward and a contract was signed on Monday to enable the airport to continue to be managed, operated and developed by LLAOL to 2031.
Councillor Robin Harris said: "Given London Luton Airport's position as the single biggest asset owned by the people of Luton, this agreement and its potential benefits for wealth in the region's economy are momentous."
Managing Director of LLAOL, Glyn Jones, said the agreement would allow it to "continue to deliver sustainable growth together, developing the airport in a positive way for partners, residents and passengers".
A planning application will be lodged by LLAOL in the autumn and will be subject to public consultation by the Local Planning Authority.