The agency picked up the business following a pitch against four undisclosed rivals. It is the first time that the hotel chain has hired an ad agency, and BMB will promote the company across Europe as it further expands into the continent.
RFH's developments will include hotels in Munich and Prague, as well as a Sicilian golf resort.
In addition to developing traditional above-the-line ads, BMB will develop marketing design concepts and a digital customer relationship management strategy.
RFH owns upmarket hotels including Brown's in London's Mayfair, Edinburgh's The Balmoral, the Hotel Astoria in St Petersburg and the Hotel de Russie in Rome.