Latest figures show international commodity prices rose for a fifth consecutive month in July, a sign the global economy is improving.
The ANZ Commodity Index recorded a 1% rise as eight commodities increased in price and five fell.
But looking at the index in New Zealand dollars, commodities recorded a minor increase in prices of 0.1% due to a higher dollar.
Aluminium topped the price increases, with a 6.7% rise, followed by three forestry products.
ANZ economist Steve Edwards says he expects exporters to continue to feel the pinch as the high New Zealand dollar offsets increases in commodity prices.