No sign of Prestwick airport sale
The New Zealand company which owns Prestwick has said there is no sign of a buyer for the airport, and its value has fallen.
Infratil put its two UK airports, which include Kent, up for sale in March this year.
However it said the sales process for both had been "unsuccessful to date".
As a result, Infratil said it had taken an impairment charge of £22m, which now values Prestwick at about £14.3m and Kent at £7.6m.
Infratil said that it would "continue to seek a buyer for the airports and work with local stakeholders to review alternatives".
Together Prestwick and Kent's Manston Airport recorded losses for the six months to the end of September of just over £2m.
Passengers travelling through the airports fell by more than 180,000 during the period compared to the same time in 2011, although freight business increased.
Prestwick airport has had several owners in recent years.
In 1991 the newly-privatised British Airports Authority, BAA, put it on the market.
In 1992 the airport was bought by Canadian businessman Matthew Hudson. He sold it in 1998 to transport group, Stagecoach.
Stagecoach then sold it to Infratil in 2001 for £33.4m.
A significant percentage of the airport's aviation revenue is derived from freight and other aircraft activity, with business and property income also playing a significant role.