Federated Farmers in October said there were concerns about the transfer of shares to the custodian, including who would run it and whose interests it would have at heart.
Fonterra chairman Sir Henry van der Heyden said the trading among farmers plan was on track for introduction in November next year but that there were concerns among some people about the proposed custodian.
Fonterra said chief executive Theo Spierings had acknowledged the concerns at the company's annual meeting and undertaken to come back to farmers with possible alternatives before Christmas.
"Next year, we will outline three options, the current custodian proposal, a second option that offers some important changes to the current proposal and a third option which gives legal title to farmers," Spierings said.
The details of the options were being worked through and would go to a board meeting next month before going to the Shareholders' Council and then being discussed with farmers at meetings to be held between January 31 and February 3.
Spierings said the board had insisted it must be able to unfold the fund in the unlikely event it was not working. He said some farmers were worried that the Shareholders' Fund might get too big. There was a 20 per cent limit on the number of production-backed shares that could be subject to contracts with the fund and there was no intention of allowing the fund to get anywhere near that level.
"We have talked about $500 million - that is 8 per cent and much closer to the mark. It is likely to sit somewhere between 7 and 10 per cent."