Irish independent retailers group RGDATA is up in arms about a 7% price rise by Ireland's biggest milk producer Glanbia. It claims the increase discriminates in favour of the multiples. Averaging 4.6p a litre, the rise is calculated on total sales volume. Major chains like Tesco and Dunnes, which have a 30% margin, will escape lightly because of the quantities they sell. In contrast, small retailers operate on a 15% margin, but will be fearful of passing on the price rise to the customers in case they lose trade to the large supermarkets. RGDATA has filed a complaint with Director of Consumer Affairs Carmel Foley. Director general Ailish Forde said: "The way in which this price increase is being applied, with independent retailers targeted, is not fair and equitable under competition law." Glanbia, formed through the merger of Waterford and Avonmore dairy co-ops, has a 50% share of the Irish liquid milk market, with 70% of the lucrative Dublin trade. {{NEWS }}