"It appears there simply weren't enough buyers willing to pay any higher prices to absorb the extra supply on offer," AgriHQ dairy analyst Susan Kilsby said in a note.
Fonterra made 12,850 tonnes of whole milk powder available, Ms Kilsby noted, adding that there was 6% more whole milk powder available for buyers than at the previous auction.
Even so, however the volume available was still less than was offered at this time a year ago, according to Ms Kilsby.
At the latest GDT auction, lactose fell 2.9 percent to US$836 a tonne, while rennet casein declined 2.7 percent to US$6,234 a tonne.
Anhydrous milk fat slipped 0.6 percent to US$5,352 a tonne.
Meanwhile, butter rose 0.5 percent to US$4,308 a tonne, while cheddar added 1.4 percent to US$3,894 a tonne.
Skim milk powder gained 2.3 percent US$2,660 a tonne, while butter milk powder increased 4.5 percent to US$2,670 a tonne.
The New Zealand dollar last traded at 69.27 US cents at about 12.15pm in New York, compared with 69.24 US cents at 5pm in Wellington the previous day.
There were 120 winning bidders out of 151 participating at the 13-round auction. The number of qualified bidders rose to 523, up from 520 at the previous auction.
