Andrew Lloyd Webber has said he would be interested in buying Highclere Castle to house his art collection.
Lord Lloyd Webber has approached planning chiefs with an offer for the landmark on the Hampshire-Berkshire border.
Owners Earl and Countess of Carnarvon are applying for permission to build up to 15 houses on the site, near Newbury.
They want to fund much-needed repairs to some of the historic buildings.
But they have said the castle is not for sale.
The “enabling development” plan – not usually permitted – may be considered because of the benefit to the historic buildings and talks are continuing, Basingstoke and Deane Borough Council said.
A spokeswoman said Lord Lloyd Webber, who lives on the nearby Sydmonton Court estate in Hampshire, had written to the council expressing an interest to buy the castle should it come up for sale.
In a letter to the council, Lord Lloyd Webber said: “I am longing to provide a permanent home for my art collection. The combination of Sydmonton and Highclere would provide exactly that.
The Countess of Carnarvon said they would not sell the castle
“If the Earl of Carnarvon were to sell the estate he would obviously want an open market price but this has not been tested.