WELLINGTON -- New Zealand's exports and imports last month were both up from May last year, with China leading increased demand for New Zealand exports, the government's statistics agency reported Monday.

Merchandise exports were valued at 4.6 billion NZ dollars ($3.69 billion), up by 429 million NZ dollars, or 10 percent, from May 2010, said a report from Statistics New Zealand.

China recorded the largest increase among importers of New Zealand goods, up by 24 percent, or 109 million NZ dollars across a range of commodities, including pine logs (up by 51 million NZ dollars); fish, crustaceans, and molluscs (up by 22 million NZ dollars); and frozen lamb (up 15 million NZ dollars).

These were slightly offset by a fall of 13 million NZ dollars in sales of milk powder, butter, and cheese.

The Marshall Islands had the second-largest increase, up by 95 million NZ dollars due to exports of pleasure boats, said the report.

Exports to Australia also increased, up by 43 million NZ dollars, or 4.7 percent, with sales of crude oil up by 15 million NZ dollars and mechanical machinery and equipment up 9 million NZ dollars.

"The 429-million-dollar increase in exports was led by pleasure boats; milk powder, butter, and cheese; and meat and edible offal, " said Statistics New Zealand business, financial, and trade manager Neil Kelly.

"China was the country with the largest increase".

The May trade surplus was valued 605 million NZ dollars, or 13 percent of the value of exports, compared with an average surplus of 6.7 percent of exports over the May months from 2006 and 2010, said the report.

Merchandise imports were valued at 4 billion NZ dollars, up by 594 million NZ dollars, or 17 percent, from May last year.

A one-off import of aircraft parts valued at 214 million NZ dollars contributed to the rise, but crude oil was also a major factor, up by 118 million NZ dollars, or 32 percent.

The trend in the value of exports had increased 30 percent since its most recent low point in September 2009, while the trend in import values had mainly increased -- up by 22 percent -- since the most recent low point, also in September 2009, but was still 8.6 percent below its overall peak in September 2008.