Leo Burnett was hired by Numico, the Dutch baby food maker in August, following a global pitch. After the appointment, Numico was acquired by Danone for an estimated £9.7m.
The Paris-based maker of Activia yogurt and Evian and Volvic bottled water has now awarded Leo Burnett's place on its Numico roster to Euro RSCG, despite it losing out in the competitive pitch against Leo Burnett last year.
Leo Burnett handled projects for Numico's Cow & Gate and Milupa brands and once it finishes working on these briefs, the Publicis-owned agency will not be handed any further work. The UK spend is estimated to be around £4.2m.
The move comes just days after Danone reported first half-earnings that showed net profit growing 15.8% to €701m (£554m) on sales of €7.7bn.
Danone's fresh dairy division, its largest, was held back by worsening market conditions in France in the second quarter, with overall volumes falling 1.5%.
The company's water business's performance was "disappointing" as weak demand in France, Spain and the UK drove a drop in volumes in Europe during the second quarter.
But the drop was offset by an "outstanding" quarter for Danone's baby nutrition division, which includes the operations of recently acquired Dutch baby food maker Numico, thanks to strong demand in the UK, Germany and the Netherlands.