WELLINGTON, March 21 (Reuters) - International milk prices fell for the fourth straight dairy auction, New Zealand's Fonterra Cooperative Group, the world's biggest dairy exporter, said on Wednesday.
Fonterra's Global Dairy Trade-Trade Weighted Index, which covers a range of 30 products and contract periods on offer, dropped 4.5 percent, with an average selling price of $3,396 per tonne.
All prices fell, led by milk protein concentrate, casein and cheddar.
The index has fallen nearly 30 percent since hitting a near four-year peak in March last year as global commodity prices retreat.
Full details of the auction are at: www.globaldairytrade.info
Fonterra holds two auctions a month, with the next one on April 4.
The co-operative last week lowered its payout forecast range for the 2011/2012 season by 15 NZ cents to NZ$6.75-NZ$6.85 a kg of milk solids, reversing increases announced in December, because of softer prices and a strong exchange rate.
The payout for the 2010/11 season was a record NZ$8.25 a kilo on record production and sales.
Fonterra is owned by about 10,500 farmers and controls around a third of the world's dairy exports, generating more than 7 percent of New Zealand's gross domestic product. (Reporting by Mantik Kusjanto)