New Zealand's merchandise exports rose to their highest ever for an April month as increased dairy prices boosted the value of the country's largest commodity for a seventh consecutive month.

Exports rose 9.8 per cent to $4.75 billion in April, setting a new record for the month and marking the third-highest month ever recorded behind the $5b of exports in March 2014 and $4.9b in March 2015, according to Statistics New Zealand.

Dairy exports in April jumped 35 per cent to $1.11b, driven by higher prices. Milk powder values increased 27 per cent, or by $117b, while the quantity fell 11 per cent, and the value of milk fat products rose 55 per cent, or by $86 million, with the quantity lifting 4.6 per cent, Stats NZ said.

The country's top five export commodities all rose from the year earlier month. In order of their ranking, meat exports lifted 1 per cent to $630m, wood exports gained 18 per cent to a new record of $406m, fruit exports advanced 3.4 per cent to $444m and wine exports jumped 20 per cent to $136m.


Meanwhile, goods imports also advanced in April, lifting 4.9 per cent to $4.17b, setting a new record for an April month. The main movements were in intermediate goods, led by petroleum, and capital goods, led by mobile phones, portable computers and tractors, the statistics agency said.

The export gains led to a goods trade surplus of $578m in April, the largest monthly trade surplus since March 2015 and the largest April surplus since 2011, Stats NZ said.

The annual trade deficit reduced to $3.48b in April from $3.71b in March and $3.8b in February, which was the highest in almost eight years.

"NZ's trade balance was stronger than expectations over April, with the $578m surplus higher than the market ($267m) and our ($50m) expectations," ASB Bank economists said in a note. "Over the remainder of 2017, we expect the underlying trade balance to improve further, reflecting healthy meat and dairy export prices and lifting agriculture production."