One of the participants in the Global Dairy Trade (GDT) has baled out, as calls mount for Fonterra to suspend its use of the on-line auction platform.
The calls from some farmers and political parties come in response to the continuing slide in prices for dairy products sold in the twice-a-month auction.
Fonterra said the GDT was not to blame for the low prices, which were due to the world oversupply of dairy products.
GDT director Eric Hansen said the system was working as it should and was continuing to provide internationally recognised market-based benchmark prices.
He said last week's auction saw an increase in the number of bidders and an increase in demand across all products sold on the platform.
But one of the companies that have been using GDT has withdrawn from the auction.
Land O'Lakes - an American food and agricultural cooperative - only joined in March last year to sell skim milk powder.
But it has not sold anything through GDT since January and has not offered any product for the past six months.
It said it was withdrawing from the auction to focus on other sales channels.
New Zealand First leader Winston Peters said a European dairy co-op, Molkerei Ammerland, also stopped using GDT in April.