NZ manufacturing activity fell in the three months to March – the first seasonally adjusted fall since September 2011.
Figures issued by Statistics New Zealand show volumes fell a seasonally adjusted 0.6 percent in the March quarter, led by a fall in metal product manufacturing.
A slump in aluminium production was a major contributor to the slowdown.
The fall follows five quarters of increases.
Statistics NZ said the trend for the manufacturing sales volume, which gives a longer-term picture of movements, has been rising since late 2011 but now appears to be flattening.
Of the 13 manufacturing industries, six were down in the March 2013 quarter, Statistics NZ said.
Total manufacturing sales value edged up 0.2 percent to a seasonally adjusted $22.9 billion.
Economists warn the weakening of the Australian dollar could impact on the demand for goods from New Zealand.
New Zealand's manufacturing sector employs 250,000 people.