The Reading Festival and WOMAD Rivermead could be forced to find alternative homes, with the owners of the site intent on selling the land for £1.5m.
Little John’s Farm in Reading has been put on the market, meaning both festivals could be forced away from their long standing homes.
Reading has been based there since 1971 and WOMAD since 1990.
It is understood that there is a plentiful supply of gravel and sand beneath the surface of the fields, which would be worth millions to the building industry.
Its proximity to the Thames means it could also be developed for luxury housing.
Festival organiser Mean Fiddler has a lease on the site until 2010, meaning the festival will be secure until then.
The firm’s MD Melvin Benn conceded he would be looking at alternative locations, but said he was confident the festival would not have to move.