An undisclosed number of bidders have been invited to lodge detailed offers to buy Prestwick Airport, The Scotsman has learned.
It follows the Scottish Government revealing several initial bids had been submitted by the deadline for expressions of interest last week.
The buyer – or “preferred bidder” – is expected to be selected around 6 September and the sale completed around 4 October, according to the sale documents.
The move comes six years after ministers bought the South Ayrshire site for a token £1 to avert its closure, taking on losses of some £7 million a year. It has since received £39.9m in loans from the Scottish Government, which has not clarified whether these would have to be repaid by the buyer.
A Scottish Government spokesman said: “The invitation to tender documentation will be issued on the 26 July, as outlined in the sale documentation.
“To protect the integrity of the process we will not be making any further comment and will update Parliament at the appropriate time.”
Ministers have denied a buyer was identified before the sale process was launched last month.
However, unions at the airport are understood to believe firm interest from a potential buyer triggered the sale announcement on 13 June.
They believe the tendering process is just to “tick all the boxes”.
There is concern about whether a buyer would be motivated by the prospect of acquiring the site on the cheap and selling off some of its land for development.
It is understood the airport’s attractiveness may have increased by operating losses being reduced to around £2m a year.
However, it still has only one airline – Ryanair – which flies just 670,000 passengers a year, a fraction of the millions at rivals Glasgow and Edinburgh.
Scottish Labour transport spokesman and south Scotland MSP Colin Smyth said: “Changes made by the new management team have certainly help stem the airport losses, making it a more attractive proposition.
“I hope therefore that the expressions of interest made so far develop into a credible bid and a sustainable future for the airport.
“I would doubt the whole sale process would have started had there not been clear interest. But it is vital any sale isn’t simply a way for the Scottish Government to wash its hands of Prestwick.
“It must ensure there will be no sale to a company that does not guarantee to secure and grow jobs, and any sale should be subject to agreement that the tens of millions of pounds of taxpayers’ money loaned to the airport will be paid back in full by any new private owner.”