New Zealand commodity prices edged up to a new record in May, led by kiwifruit at the start of a new season. Prices in New Zealand dollars fell from a record level as the kiwi dollar climbed to a post-float high.

The ANZ Commodity Price Index rose 0.3 per cent in May, the smallest gain of nine consecutive increases, following a 1.6 per cent gain in April. The New Zealand dollar recently bought 81.97 US cents, having reached 82.62 cents yesterday, the highest since being allowed to trade freely in March 1985.

Prices of kiwifruit jumped 27 per cent and were up 19 per cent from the same time last year.

Prices of skim milk powder, lumber, cheese and sheepmeat all rose 2 per cent, while skins gained 4 per cent. Log and venison prices advanced 1 per cent and seafood gained 0.3 per cent.

The monthly commodity price series comes after trade data this week showed primary produce drove the trade surplus to a record $1.1 billion in April and figures today showing the terms of trade rose to the highest level since 1974 in the first quarter.

In May, prices of nine commodities rose, six fell and two were unchanged, of the 17 monitored in the ANZ report.

Apple prices fell 7 per cent, beef declined 5 per cent, whole milk powder dropped 4 per cent, aluminium fell 3 per cent and wool fell 0.3 per cent, its first decline this year.

Prices of wood pulp and casein were unchanged.

The aggregate NZD Commodity Price Index fell 0.8 per cent though ANZ economist Steve Edwards said it remains "elevated" and is 12 per cent up from a year earlier.