Prestwick airport is now owned by the Scottish government after being bought for £1.
The BBC reports the airport, which was put up for sale last year by Infratil, has incurred annual losses of £2 million.
It is understood a deal was concluded late on Friday. It is expected the airport will continue to operate as normal.
Deputy First Minister Nicola Sturgeon said the full terms of the agreement with Infratil and the Scottish government's business plan for the facility would be made public at a later date.
She said the government would run the airport on "a commercial basis" and do everything it could to return it to profit as soon as possible.