Ryvita sales and marketing director Philippe Seurre said the agency's work on the McVitie's Go Ahead range of reduced-fat products was seen as a conflict of interest.
"Publicis has played a considerable role in taking the brand forward over the past few years, but this conflict of interest has brought about the need for change and we look forward to developing Ryvita further in the future," he said.
Media for the brand is handled by Optimedia and will not be reviewed said Seurre.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .