Burkitt DDB has won pounds 6 million of Hasbro business from TBWA/London following the toy and games giant's European consolidation of its international creative account into DDB.
The win means that brands that were previously handled by TBWA, including Playdough, Playschool, Barney the Dinosaur and the Tweenies will move to Burkitt DDB.
The agency already handles Action Man and Monopoly.
Under the agreement, the existing media planning and buying relations in each market will not be affected.
The consolidation was triggered by Hasbro Europe's sourcing of extra creative work from the US, coupled with the increasing portfolio of Hasbro toys, games and lifestyle products.
Hasbro Europe announced nine months ago that it intended to consolidate its business into one agency network.
Hasbro was a founding client for Griffin Bacal in the 70s. The agency merged with Court Burkitt to bolster its presence within the DDB network in June.
Griffin Bacal wrestled the pan-European K'nex brand, also owned by Hasbro, from J. Walter Thompson six months ago.
Jonathan Hoare, the managing director of Burkitt DDB, said: 'We're delighted to have won this extra business. It's always a great thing when one of your key clients gives you that vote of confidence.'