The company formerly known as BAA is to sell Stansted airport to the Manchester Airports group for £1.5 billion.
The deal, announced late this evening, will mean that BAA - now known as Heathrow Airport Holdings - will be responsible for just four UK airports compared with its original seven.
The remaining ones are Heathrow, Southampton, Aberdeen and Glasgow.
Stansted Airport is under new ownership this morning. It has been sold for £1.5 billion pounds by Heathrow Airports Holdings to Manchester Airports Group. Stansted is London's third busiest airport and handles around 17 million passengers a year.
Stansted Airport has changed hands and the new owners already have problems to deal with. The biggest airline to use the airport, Ryanair, is angry about a 6% increase in airport charges and says it may pull some of its flights out.
Stansted has been bought by M.A.G. which owns or operates Manchester, East Midlands and Bournemouth airports. Stansted's former owner was forced to sell by the Competition Commission.
Click below to watch a report from ITV News Anglia Business Correspondent Matthew Hudson: