Higher dairy costs have driven up the prices producers pay for their inputs, and receive for their goods.
Official figures show the producers' output prices rose 2.4% in the three months to September, compared with the previous quarter, the highest quarterly rise in five years.
This was largely driven by increased dairy prices, while electricity and gas prices fell.
The producers' input prices, which is a measure of wholesale inflation, rose 2.2% - also largely influenced by a rise in dairy product manufacturing prices.
A Westpac senior economist, Michael Gordon, says the gains were fairly steep.
"We were expecting an increase this time," he says.
"That index is quite heavily weighted towards things which are produced in New Zealand and sold overseas.
"It's not so much an issued of domestic inflation, but probably more a reflection of export prices, and we know there was quite a substantial increase in the payout forecast for dairy in particular over the September quarter, and that was quite a big driver of the index this time," said Mr Gordon.
Separately, the price of purchasing new capital items rose 0.4% in the September quarter, because of the higher prices for buying and building new houses, including material and labour costs.
For the year, the capital goods index rose 0.9%.
