The account, believed to be worth around £140,000 a year, includes a brief to raise the profile of the French-owned firm's profile in the lifestyle pages of the mainstream media.
Brighter PR will also handle the press office function covering both consumer and trade press and crisis management.
Next month the ferry operator will be launching a new cruise ferry, the £80m Mont Saint Michel, with another - the £100m Pont-aven - to launch in 2004.
Brittany Ferries MD David Longden said: 'We had been working with that company (CIB) for a long, long time and we were extremely satisfied with the service that they have been giving, but we wanted to see what else was out there as we embark on a considerable investment.'
The Brighter team is headed by MD Steve Dunne who reports to Longden.
Handling PR for Brittany Ferries Holidays is also included in the brief.
Brittany Ferries was founded in 1973 and is owned by BAI, a co-operative of French farmers, hoteliers and Normandy and Brittany-based businesses.
The firm has a current six strong fleet and has routes to Normandy, Brittany, Spain and Ireland via France.