Harbour Hotels has acquired the grade II-listed 37-bedroom Ship Hotel in Chichester from the Chichester Hotel Company for more than the £6m guide price.
The Georgian property, located within Chichester's Roman Walls, also includes a private cottage overlooking Priory Park and a refurbished restaurant.
It was offered with detailed planning consent for a large extension to include 25 additional bedrooms, extra function facilities and undercroft parking.
Current bedrooms are themed in the style of recent productions at the nearby Festival Theatre.
John Chesterman of Chichester Hotel Company said: "We have been very proud to own the Ship Hotel and have, over the last 10 years, restored this grand hotel to its former glory. It's been a privilege to work with the wonderful staff and watch the Ship play its part in the phenomenal growth of the city over recent years."
Mike Warren, managing director of Harbour Hotels, added: "We are very excited to be taking the Harbour Hotels brand to Chichester; it's an exciting location and a key strategic position from our perspective. The Ship is a prestigious, landmark property with some outstanding features. There is an excellent team of staff at the property and we are delighted to have such an addition to the Harbour Hotels portfolio."
The latest acquisition follows Harbour Hotels' recent announcement of new properties in Brighton, Bristol and South Sands (Salcombe). The Ship Hotel will be re-branded as a Harbour Hotel in early 2016, taking the total number of properties within the company's portfolio to 13.
Chichester Hotel Company was represented by Savills in the sale of the property.