Kelham Hall & Country Park in Nottinghamshire has been put on the market with a guide price of £10m.
The Grade I-listed, 19th-century property was bought by Jonathan Pass's Kelham Hall Company in November 2014 from Newark and Sherwood District Council, which previously used the building as its headquarters. The council originally put the property up for sale in 2012 for £5m but dropped it to £2.5m in February 2014.
The former stately home was set to be refurbished in 2018, having gained planning permission in December 2017 to turn it into a 103-bedroom hotel, spa and wedding venue.
According to Christie & Co, the owner has "invested heavily in the estate in order to secure full planning and listed building consent from English Heritage as well as discharging all the prestart planning conditions associated with the hotel and spa development scheme".
The Victorian estate was designed by Sir George Gilbert Scott as a precursor to his London St Pancras train station. It includes around 44 acres of formally designed landscaped gardens and parkland and is situated on the banks of the river Trent.
Ryan Lynn, director of corporate hotels at Christie & Co, who is handling the sale, said: "We are very pleased to be marketing this fantastic development opportunity in the heart of Nottinghamshire.
"Kelham Hall is one of the most iconic and historic buildings in the area and offers a buyer the chance to create what could be one of the best hotels in the country. This is a great opportunity for a buyer to secure a substantial property and redevelop it over the next 12 to 24 months, allowing the business to open into a resurgent market."