The company has shifted focus from pubs and brewing towards restaurants and budget hotels.
Whitbread head of external communications Abigail Langan said the company had already decided to take PR for coffee chain Costa in-house. The review could also mean a radical shake-up of PR for restaurant chains Brewers Fayre, Beefeater and TGI Friday's.
CompanyCare, which handles PR for Costa, is the first casualty of the review. Langan said Whitbread's comms team would handle all future PR for Costa, though it might engage agencies on a project basis.
CompanyCare is also retained on Beefeater and TGI Friday's, while Euro RSCG Leedex was enlisted to work on Brewers Fayre last year. The review does not affect Whitbread's non-restaurant businesses, David Lloyd Leisure and Premier Travel Inn. David Lloyd Leisure does not retain an agency.
Whitbread promoted Langan earlier this month from luxury hotel chain Marriot UK where she had been head of communication.
The rethink comes in the same week that Whitbread warned it was seeing a slowdown in consumer spending at its pub restaurants, despite announcing an 18 per cent rise in full-year pre-tax profits to £249m.
Chief executive Alan Parker said it would open fewer outlets than previously planned.