The Cabinet Office has appointed agents to sell a 79-acre site in Ascot, Berkshire.
Gerald Eve has won the mandate to bring to market Sunningdale Park, which includes a Grade II listed Georgian mansion and a conference centre.
Government Property Unit executive director Bruce Mann said: “We have a rigorous programme to ensure the best use of the land and property held by government, to dispose of what we don’t need and to drive down the cost to taxpayers of what we keep.
“The publication of the Development Opportunity Brief on Sunningdale Park signals our intention to dispose of the site and get best value for taxpayers.”
Buildings on the site, which total 215,000 sq ft, include the former home of the National School for Government.
Although the site is in the green belt, the GPU has proposed a series of development options, including the redevelopment of existing buildings to provide new homes.
It is working with local planning authorities to set out a framework for future uses of the park. Formal marketing of the site will start next year.
