Little-used Prestwick airport is being put up for sale by the Scottish government.
It passed into state hands after being bought by the Edinburgh government for £1 in late 2013 after being threatened with closure following heavy losses.
Transport Scotland said an advert would be placed in the Official Journal of the European Union, inviting expressions of interest, the BBC reported.
Ministers have regarded the airport as a strategic economic asset, particularly for Ayrshire.
But Ryanair is the only airline to offer regular commercial flights from Prestwick with a network of 14 destinations.
This is despite the airport having a terminal capacity for 2.5 million passengers which could expand to handle more than ten million a year.
Prestwick also has the longest runway north of Manchester together with a second runway.
Scottish transport secretary Michael Matheson said: “Since the Scottish government bought Glasgow Prestwick airport in 2013, we have been clear that it is our intention to return the business to the private sector when the time is right.
“The senior management team at the airport has continued to engage with potential buyers and investors to discuss proposals for developing the business under new ownership.
“Good progress continues to be made by the airport to increase revenue, deliver operating efficiencies and pursue exciting opportunities for the future, including Spaceport.”
Any expressions of interest would be “considered carefully” before any decision was taken to divest the government’s shareholding in the airport or any part of the business, he added.
Ayr MSP John Scott said: “Prestwick has all the foundations for success – the longest commercial runway and parallel taxiway in Scotland, a reputation of being Britain’s only fog-free airport, its own dedicated railway station, and a thriving aerospace campus.
“What it now needs is an owner prepared to put in the investment to take the airport forward as the major economic asset it undoubtedly is.”