The transport secretary has said he will draw up new plans for Prestwick Airport if a buyer cannot be found.
Michael Matheson said that despite a 4 October deadline passing, bids for the state-owned airport were still being considered.
The airport was taken into public ownership six years ago after being threatened with closure following heavy losses.
The Scottish government announced plans to sell the airport in June.
In a letter to Edward Mountain MSP - convenor of the rural economy and connectivity committee - Mr Matheson said he was limited in what he could say about the private bidders interested in running the Ayrshire airport.
However, he added: "Good progress continues to be made and we are satisfied with how the sale process is developing.
"I have committed to providing an update to Parliament once I am in a position to do so, while respecting the need to maintain confidentiality for commercial reasons."
Mr Matheson said that while efforts currently focussed on returning the airport to the private sector, "should this not be achievable for any reason we will consider options for taking the airport forward in the future," he said.
Transport Scotland placed an advert inviting "expressions of interest" in Prestwick Airport in the Official Journal of the European Union earlier this year.
Ministers have regarded Prestwick Airport as a strategic economic asset, particularly for Ayrshire.
It passed into state hands after being bought by the Scottish government for £1 in late 2013.
In January, it emerged that the debt owed by Prestwick to the Scottish government had risen from £30m to £38.4m.
A preliminary date for the conclusion of the sale had been initially drawn up by the government for 4 October.
A spokesman for Transport Scotland said the 4 October deadline "was only ever indicative and intended as a guide for prospective buyers."