Gatwick Airport has today been put up for sale by operator and owner BAA.
The move has been forced on BAA after the Competition Commission signalled its intention to break up its monopoly.
The sale of Gatwick Airport is a "landmark moment" in the airport's history but it is "business as usual" for those involved in the airport's multi-million expansion plans during the sale process, according to Gatwick Airport managing director Andy Flower.
"Today's announcement by BAA represents a landmark moment in the long and proud history of Britain's second largest airport. I know this was a difficult decision for BAA to make, but it is the right one for staff, passengers and customers. We can now begin to address the uncertainty which has been fuelled by nearly two years of speculation about our future.
"Whatever the outcome of this process, I know that Gatwick will have a successful future. The airport will continue to play a vital role in the community, supporting the local, regional and national economies.
"We have exciting plans in place to revitalise the airport and transform the passenger experience over the next five years and a strong team focussed on making Gatwick a great airport. It is business as usual at Gatwick."
Colin Matthews, BAA's chief executive, said he still disagreed with the Competition Commmission's findings, but that the decision to sell would remove uncertainty for the airport's customers, staff and business.
He added that the company remains committed to Stansted and that a change of ownership there would hamper efforts to secure a second runway.
"At Stansted, we believe that a change of ownership would interfere with the process of securing planning approval for a second runway, which remains a key feature of Government air transport policy.
"The Commission itself states that a shortage of runway capacity in the South East is a main cause of poor service standards, but we believe its proposed remedies will delay delivery of that capacity."
BAA will appoint financial advisers soon.
Gatwick is the busiest single-runway airport in the world and the second largest airport in the UK. Its development strategy for the future focuses on the airport's expansion as a single-runway, two-terminal airport, as it grows to handle around 40 million passengers a year by 2010/2011.