Invitation to Britain, which showcases the UK's tourist attractions, is being published by VisitBritain, a new umbrella organisation formed earlier this year by the merger of the British Tourist Authority and the English Tourism Council.
John Brown was confirmed on the business after a pitch against a number of undisclosed contenders. Production of the guide was previously handled in-house.
The appointment comes as Britain attempts to win back the thousands of American tourists who are fearful of flying to the UK because of terrorist threats.
The guide, which will have 26 editions and be published in 19 languages, will be distributed via a number of routes, including travel fairs.
Sandie Dawe, the VisitBritain communications director, said: "I'm confident it will be an important tool in persuading potential first-time visitors to make a trip."
Andrew Hirsch, John Brown's chief executive, said: "We're very proud to have been chosen for such a high-profile task."