Red Carnation Hotels has bought Egerton House hotel in London's Knightsbridge for an undisclosed sum.
A four-storey, 30-bedroom property originally opened in 1990, the hotel was owned by Franklin Hotel Investments.
Red Carnation already owns the Montague, the Rubens, the Chesterfield, and the Milestone in the capital.
Franklin is in discussions to sell another London property, the Franklin in Knightsbridge. Its Dukes hotel, also in the capital, is not on the market despite earlier reports.
No one at Franklin or Red Carnation was available to comment.
The sale was a joint instruction for property agents Jones Lang LaSalle and Knight Frank.