Global dairy prices fell in the overnight Global Dairy Trade auction for the third consecutive time
Prices at the fortnightly sale fell by 3.6 percent to an average of $US2,620 a tonne.
However the drop was not as steep as the 10.8 percent decline at the start of the month.
A key price that determines Fonterra's payout to farmers, whole milk powder, fell by 4.3 percent to $US2446.
The amount of product sold at the auction increased by 2,434 tonnes to 25,596 tonnes.
Analyst Susan Kilsby of AgriHQ says a further fall was expected because there was still an over supply of milk in the world.
She expected supply and demand to come back into balance within six months or so, allowing prices to pick up again.