The appointment follows last week's Campaign exclusive that Unilever Bestfoods was looking beyond its agency "club" to find an agency to promote Carb Options as an alternative to the Atkins Diet, whose success has seriously hit sales of Unilever's Slimfast.
Ogilvy & Mather, which handles Carb Options in the US, had been working on the UK launch. But it is understood that Unilever chiefs had become concerned by O&M's failure to crack the creative brief with the launch looming.
As a result, the company opted to let Mother, another of its roster agencies, present creative ideas along with FCB. Nobody at FCB was available to confirm the win.
It is believed Unilever is ready to earmark up to £7 million a year to support the Carb Options range, which will be available in major supermarkets from early next month. Media planning and buying will be handled by Initiative Media.
Launching under the Hellmann's and Knorr brand names, the Carb Options range includes pasta, cooking sauces, dressings and soups. It aims to present itself as an alternative to faddy diet regimes such as Atkins and to appeal to consumers who want to eat healthily but still enjoy their food.
Unilever claims that only a small percentage of people are following strict low-carb diets, while many more are choosing to watch their carbohydrate intake.
Carb Options reduce or replace carbs, especially refined sugars and starch, with fibre, soy or wheat protein without increasing fat or calories.
The appearance of the new range reflects a belief by food manufacturers that while the popularity of Atkins may peter out, its legacy will live on as consumers maintain their awareness of carbohydrates for some considerable time to come.
The appointment of FCB renews the link between Paula Quasi, the senior Unilever marketer who led the pitch, and Al Young, the agency's creative director. Both worked on the Pot Noodle brand when Young was a senior creative at HHCL/Red Cell.
Jonathan Rigby, the FCB managing director, was previously the head of account management at Lowe, also a Unilever Bestfoods roster agency.