WELLINGTON - New Zealand's biggest goods export, dairy products, fell NZ$377 million ($270 million), or 19 percent, in December 2020, compared with the same month in 2019, the statistics department Stats NZ said on Thursday.

The drop in dairy exports was mainly due to a fall in sales to New Zealand's biggest export market, China, according to Stats NZ.

Total dairy exports to China fell 21 percent to NZ$740 million in December 2020. This was led by falls in milk powder, it said.

"This is also the first time in six years that there has been a fall in dairy product exports to China in the December month," international trade manager Alasdair Allen said in a statement.

The large fall in dairy exports was a key factor in total exports falling NZ$149 million in December 2020 compared with December 2019, Allen said, adding dairy export values and volumes both fell in December, compared with the same month a year before.

Typically, monthly dairy exports rise towards the end of the year, with a peak in December, Allen said, adding, "For the first time since 2008, dairy exports fell between November and December."

Dairy exports fell in the month despite a slight rise in milk production in the 2019-2020 season, with dairy cow herd numbers relatively steady, he said.

Leading the total falls in December 2020 were milk powder, butter and milk fats, he added.