Average prices of dairy products fell from a three-month high in Fonterra's latest online auction, as commodity prices and equity markets weakened on doubts about the pace of US economic growth and Greece's debt woes.

The GDT-TWI Price Index fell 2.6 per cent to US$4,324 a metric tonne, according to results posted on the globalDairyTrade auction website. That follows a 4.5 per cent gain in the previous auction two weeks ago.

Skim milk powder led the decline in the latest auction, with the average price dropping 7.1 per cent. Anhydrous milk fat fell 5.9 per cent. Milk protein concentrate and rennet casein declined 0.3 per cent and 2.4 per cent respectively. Whole milk powder climbed 2.6 per cent.

The Thomson Reuters/Jefferies CRB Commodity Index of 19 commodities was recently down 2.4 per cent and equity markets fell after European officials failed to reach accord on a rescue for Greece. US economic figures showed New York region manufacturing fell, US homebuilding confidence dropped and industrial production rose less than expected.

There were 93 winning bidders from 136 participants over 14 rounds in last night's auction. The platform has 342 qualified bidders, up from 338 in the last auction.