Beattie McGuinness Bungay has triumphed in Carling's £7 million advertising pitch, scooping the account for the lager brand.
BMB's win comes as a blow to Leith London, the incumbent on the account for the past five years. Coors Brewers' flagship lager accounted for 35 per cent of the agency's billings. Five people have been made redundant as a result of the loss.
BMB won the business in a four-way pitch against Leith London, VCCP and Euro RSCG London. It will produce a new campaign for the beer brand, scheduled to break in 2007.
Leith Edinburgh remains on the Coors roster and will continue to work on the Coors and Grolsch brands.
Carling's director of marketing, Bill Simcox, said: "The Leith Agency has delivered some great advertising for us over the past five years, during which time Carling has grown by 37 per cent in volume terms. However, in an increasingly competitive beer market, we wanted to review to ensure we have the best agency match.
"BMB has got under the skin of the Carling brand and has demonstrated outstanding passion and creativity which will translate into a new campaign in 2007."
Andrew McGuinness, the BMB co-founding partner, added: "Carling's the kind of brand we dreamed of working with when we set the business up nine months ago. We're absolutely thrilled."
Leith London won Carling, which was then owned by Bass, in August 2000.
The win built on the existing relationship the agency had with Bass, whose Tennents brand was run from its Edinburgh office.
Carling remains the UK's biggest-selling lager brand. Mintel figures valued the UK lager market in 2005 at £11.3 billion, an increase of 17 per cent on 2000 and accounting for 70 per cent of the beer market in volume terms.