New Zealand manufacturing leveled off halfway through the year, following trends offshore, according to the latest Performance of Manufacturing Index (PMI) released Thursday.

The Business New Zealand (BNZ) PMI had a reading last month of 50.2, on a scale where a reading above 50 indicates expansion and below 50 contraction.

The June reading was 5.6 points down from May and the lowest June result since 2009, said a statement from Business New Zealand.

For the first half of the year, the PMI averaged 52.7, exactly the same as the corresponding period in 2011.

Business New Zealand Executive Director for manufacturing Catherine Beard said the offshore direction of manufacturing underlined "some tough headwinds at present."

"The fall in the level of expansion for June was not strong enough to throw New Zealand manufacturing back into decline like it did in April, although the move to the middle does not inspire much celebration," Beard said in the statement.

"The JP Morgan Global PMI fell to a three-year low of 48.9 in June, which was due to inventory adjustments driving contraction. In fact, global manufacturing activity has seen a steady decline since the start of 2011, while New Zealand has managed to keep on a fairly even keel during that period, managing to keep its head above water."

BNZ economist Doug Steel said in the statement that the overall trends remained positive and indicated manufacturing made another positive contribution to GDP growth in the second quarter.

However, the FIRST Union, representing 27,000 workers in finance, industry, retail, stores and transport, said manufacturing was facing significant pressures, in particular the high New Zealand dollar.

"While manufacturing of goods from some of our primary industries, particularly dairy, remains strong, exporters of non- commodity manufactured goods are continuing to face difficult times," union general secretary Robert Reid said in a statement.

"Our high currency is punishing exporters. The government's unwillingness to aggressively tackle the fundamentals of our monetary policy settings is costing jobs."