PRESTWICK Airport will find it difficult to attract new airlines to boost passenger services after being sold, according to the man who oversaw its sale.

John Baillie, operations director at aviation consultancy MPD Group, said the Ayrshire airport needed to expand its route network and become less dependent on Ryanair to reverse the decline that has seen it lose a million passengers over the past four years.

But he said any bidders interested in buying the airport after it was put on the market last week would recognise this would be "extremely difficult".

"There are many more airports than airlines. The effort to get more airlines into airports is difficult as everyone is clamouring for new routes," he said.

"It would be extremely difficult to bring in new carriers to Prestwick but not impossible. There are probably fewer carriers operating through the UK airports than five or 10 years ago because there have been some big failures such as Flyglobespan."

Glasgow Prestwick International was purchased from Stagecoach for £33.4 million by New Zealand infrastructure company Infratil and Omniport, which sold its minority stake in the firm in 2003.

Infratil announced the sale of Prestwick, together with Kent airport, last week after admitting it was under-performing.

Experts say Scotland's fourth largest airport is likely to fetch less than £10m, though a clearer picture is expected to emerge in the coming weeks as bids are put together.