Export commodity prices fell for the fifth month in a row in October, though a weaker dollar offset most of the decline.
ANZ's commodity price index fell 3.5 per cent, the largest monthly decline since the depths of the recession in February 2009.
The index peaked last May and has fallen 7.9 per cent since then.
A weaker exchange rate absorbed most of last month's decline. In New Zealand dollar terms the ANZ index fell 0.6 per cent. It peaked last March and has fallen 11.7 per cent since then.
"The latest easing takes both the world and the NZ dollar priced indices back to the levels that prevailed at the start of the year, but encouragingly the indices remain significantly above their historical averages," ANZ economist Steve Edwards said.