Fonterra said it had revised down its 2011/12 farmer payout range by 30c to $6.45 to $6.55 per kg of milksolids.
The cooperative said its opening forecast payout range for 2012/13 is $5.95 - $6.05 per kg.
The Fonterra "fair value' share price for 2012/13 was held at $4.52.
Fonterra said its forecast for 2012/13 reflected higher dairy production around the world flowing through to lower international dairy prices.
The updated forecast payout range for this year comprised a lower forecast farmgate milk price of $6.05 per kg and a forecast net profit range of $570-720 million, equating to 40-50 cents per share.
The Global Dairy Trade trade weighted index has fallen by 20.3 per cent since Fonterra's last farmgate price forecast of $6.35 per kg in April.
"Dairy production levels in the US and Europe are high, while we continue to have higher-than-normal production levels from New Zealand,'' chief executive Theo Spierings Spierings said in a statement. "All this is occurring at a time of heightened uncertainties in global markets,'' he said.
