Fonterra said it had launched a separate milk sourcing subsidiary - mymilk - to grow its market share in the South Island.
The unit will initially invite applications, from farms in the Canterbury, Otago and Southland regions that are not currently supplying Fonterra, for one year contracts, renewable for a maximum of five years, without the obligation to purchase Fonterra shares.
Mymilk suppliers can apply to join the co-operative, purchase shares and supply Fonterra directly, at any time.
Fonterra chairman John Wilson said the scheme was aimed at those farmers who were not immediately able to buy shares in Fonterra.
"We know there are farmers who support the co-operative model, but are at the stage of development where sharing up is currently beyond their financial reach," he said in a statement.