The decision brings down the curtain on a relationship that dates back more than a decade. GGT, one of the agencies that formed TBWA/London through a series of mergers during the 90s, was first appointed to handle Cadbury's Flake in 1987.
TBWA is to be rewarded with a bonanza of petcare billings across the region after a Masterfoods decision to transfer BBDO London's estimated £40 million European Whiskas account by the end of the year. TBWA has been hired to handle the Chappie, Pal and Trill petfoods, and the organic food range Seeds of Change across the region.
"We haven't had confirmation of this and we're not able to comment, a spokeswoman for Masterfoods UK said of TBWA's appointment to the Whiskas business.
Masterfoods is likely to compensate BBDO with additional business of its own. However, the network has received new business in the shape of global appointments for Maltesers as well as the Cesar and Frolic petfood brands and Catsan cat litter.
In addition, AMV Advance will take on Skittles and Dolmio in the UK.
The TBWA president of Northern Europe, Paul Bainsfair, denied that any decision had been made to hand Whiskas to the network. "We are not working with Mars on Whiskas and we are not aware of any plans to do so, he said.
Bainsfair refused to confirm a parting of the ways with Cadbury in Europe.
However, he acknowledged that Masterfoods' decision to hand TBWA confectionery accounts in Australia had led to the network resigning its Cadbury business in that territory.
It is not clear if Cadbury will call a pitch to fill the vacant European accounts - it is working with Agency Assessments on future strategy for the brands. Euro RSCG Wnek Gosper, which handles several Cadbury brands in the UK, is a likely destination for some of the vacant accounts.
The account moves follow the May hiring of TBWA/Chiat/Day to handle the Whiskas, Uncle Ben's and Seeds of Change accounts in the US. The transfer was triggered when Mars dropped D'Arcy from its global roster.
A Cadbury Trebor Bassett spokesman said it was company policy not to comment on rumour and speculation.