Northland dairy farmers keen to switch suppliers are being forced to stick with Fonterra because of a lack of competition in specialist dairy manufacturing businesses in the region.
Dairy farmers' representatives said Northland did not have the benefits enjoyed by those in bigger regions such as Taranaki and Canterbury where new manufacturers were picking up Fonterra customers.
Rakaia-based specialist dairy manufacturer Synlait Milk and Open Country Dairy, the country's second biggest dairy manufacturer, has picked up new dairy farmers recently.
Fonterra farmers have to own shares in the co-op to supply it with milk, and some have been selling shares to supply competitors who do not require share ownership and who are offering similar farmgate milk prices.
Ian Walker, Far North farmer and president of Farmers of New Zealand, said Northland dairy farmers have no choice but to sell to Fonterra.