CheethamBellJWT has extra reason to lament losing the Kellogg's account after its animated ad for the cereal company was named the fourth most effective commercial of 2009.

The Manchester agency's ad was rated more effective than high-profile campaigns for the iPhone, Tesco and comparethemarket.com by TNS Research International.

The results are based on how likely consumers are to buy the product or service after watching an ad.

But although CheethamBell's ad was lauded for its effectiveness, the agency will not be working with Kellogg's this year after the cereal brand moved its account into Leo Burnett in November after reviewing its global agency arrangements.

David Bell, CEO of CBJWT, said: "It’s a bittersweet feeling reading of this success knowing that, due to factors outside our control, we will not be working with Kelloggs in 2010. We expect that the W.K. Kellogg we created will live on at his new agency."