The product will go on sale in February backed by a £4m ad campaign through Bartle Bogle Hegarty.
The strategy, part of Britvic's approach of offering a choice of products under each of its brands, could be used in its defence against critics of the soft drinks industry's overuse of sugar in products for children.
Robinsons For Milk was launched earlier this year. According to ACNielsen figures for the 36 weeks to 31 October, it has grown to half the size of Nesquik in terms of volume sales.
Robinsons launched a no added sugar variant of its Froot Shoot drink in 2002.