A halving of dairy exports has contributed to the 4.7%, or $214million, decline of total goods exported in May to $4.4billion, compared with a year ago.
However, the trade balance between exports and imports in May, respectively $4.36billion and $4.01billion, left a $350million trade surplus - ahead of most expectations and the fifth month in a row of surpluses, Statistics New Zealand (SNZ) data revealed yesterday.
SNZ international statistics manager Jason Attewell said at dairy's peak it made up two-fifths of total goods exports, but for May they accounted for one-fifth of total goods exported.
''Milk powder, butter, and cheese exports led the fall, down 28%, or $346million,'' Mr Attewell said in a statement.
The decline in milk powder, butter, and cheese exports was led by whole milk powder, down 37%, with quantities down 6.9%.
While whole milk powder export values to China have been low compared with last year, values to other countries have remained ''fairly stable'', he said.
Fruit exports rose $107million to $445million in May, the highest monthly value yet.
Goods imports fell $300million, or 7%, to $4 billion in May 2015, intermediate goods fell $259million, led by crude oil, and capital goods fell $80million, while consumption goods rose $4.8million.
For the year ended May 2015, the annual goods trade deficit was $2.6billion.
ASB rural economist Nathan Penny said the headline balance, of a $350million surplus, was ahead of both ASB's and market forecasts.
''Most of the surprise was due to lower import values relative to expectations,'' he said in a statement yesterday.
On a seasonally adjusted basis, dairy exports posted a small 0.3% monthly gain, reflecting the earlier and temporary strength of February prices, he said.
He noted the fortnightly global dairy auction prices did not come through in trade data until three months later.
Westpac senior economist Michael Gordon said the $350million surplus was $100million ahead of his expectations, and the market's expectations of a deficit.
''This was actually an improvement on the $246million surplus recorded in May last year. Consequently, the annual trade balance improved for the first time in nine months,'' Mr Gordon said in a statement yesterday.
He said excluding fuel, imports were down 2.6%, and there was a particularly sharp drop in imports of capital equipment.
''This is not a positive sign for the economy's near-term growth prospects,'' he said.
He reiterated that weakness in business investment was a factor in the weak gross domestic product data, earlier this month, covering the quarter to March.
