Airport operator BAA is to sell Edinburgh airport, the Spanish-owned company announced today.
BAA, which operates six UK airports, had been ordered by the Competition Commission (CC) to sell either Edinburgh or Glasgow airport.
BAA said today it had decided that Edinburgh would be the one to be sold and that - if all goes well - the sale will be agreed by next summer.
After a long inquiry, which has led to numerous legal challenges, the CC found that BAA's ownership of UK airports was anti-competitive and ordered the company to sell Gatwick, Stansted and one of either Glasgow or Edinburgh.
Gatwick has already been sold to an American concern and BAA is still disputing the Stansted decision.
BAA, which also operates Heathrow, Southampton and Aberdeen airports, said today: "We are now commencing preparations for a sale (of Edinburgh) and expect to formally approach the market in the new year with a view to agreeing a sale by summer 2012.
BAA chief executive Colin Matthews added: "Edinburgh is a great airport with a great team and a great future and we will be very sorry to see it leave BAA.
"We remain committed to Scotland and we will continue our long-term investment to improve passenger and airline experience at Aberdeen and Glasgow, as well as at Edinburgh until the sale is complete."
He went on: "Choosing which airport to sell has been a difficult decision. Edinburgh Airport has shown itself to be a strong and resilient asset throughout the economic downturn.
"Passenger numbers at Edinburgh have grown by more than 6% over the past year and in an uncertain market we expect it to be an attractive asset to prospective buyers.
"Glasgow Airport has great opportunities for future growth and development and we think BAA is well-placed to build on its recent success. Both airports are of national importance and have a bright future."
Edinburgh is Scotland's largest airport, handling more than nine million passengers a year and more than 100,000 flights.
Passenger numbers have grown by 6.1% over the past 12 months and by 9.5% since the start of 2011. Around 40 airlines connect Edinburgh to more than 120 destinations. The airport is also a burgeoning cargo hub with 10,200 tonnes of cargo in the past year.
Edinburgh directly employs 485 staff and supports 7,500 jobs across Scotland.
BAA made a £42 million investment in 2010 in the departure lounge and security hall.
Jim O'Sullivan, managing director of Edinburgh Airport, said: "Today's announcement brings the clarification that many had been calling for and although we will be sorry to leave BAA, we do so in the knowledge we are in an extremely strong and healthy position.
"Not only has Edinburgh Airport benefited from considerable investment in recent years but we have an excellent team in place which has been the driving force behind our success to date.
"We will now begin preparing for the sale process, but irrespective of who may own it, the team at Edinburgh Airport will undoubtedly continue to deliver for its passengers, the city and Scotland as a whole."
Amanda McMillan, managing director of Glasgow Airport, said: "Clearly we welcome today's announcement as it marks the end of what has been a prolonged period of uncertainty. Now a final decision has been reached we can concentrate our efforts on ensuring Glasgow Airport, as part of BAA, continues to deliver for its passengers, the city and Scotland as a whole."