WELLINGTON - New Zealand exports to China have tripled in the five years since the bilateral free trade agreement (FTA) was signed, catapulting China into place as New Zealand's second biggest export partner, according to New Zealand's official 2012 Yearbook released Thursday.

China was New Zealand's fourth largest export market for goods, taking exports of NZ$2.1 billion ($1.63 billion) when the FTA was signed in 2008, but that had leapt to NZ$6.1 billion last year, said the Yearbook published by the government's Statistics New Zealand agency.

In contrast, exports to Australia, New Zealand's biggest trade partner, rose just NZ$1.3 billion, or 14 percent, over the same period.

The boom in sales to China saw it rise from New Zealand's fourth major export destination to overtake the United States and Japan.

Dairy products, including milk powder, butter and cheese, was the most exported commodity to China, with a value totaling NZ$2.2 billion last year, up by NZ$1.8 billion from 2008.

"The 2012 exports amounted to 19 percent of our total exports of milk powder, butter, and cheese for that year. This contrasts sharply with the NZ$406 million of dairy products we sold to China in 2008 (just 4.6 percent of our total exports of milk powder, butter, and cheese)," it said.

Logs, wood, and wood articles came second, with NZ$1.1 billion in exports to China in 2012, up by NZ$867 million from 2008.

China had surpassed Australia to become New Zealand's main imports partner, it said, with total imports up 31 percent from 2008 to NZ$7.7 billion last year.

In the same period, imports from Australia fell by NZ$1.4 billion to NZ$7.2 billion.

Mechanical machinery and equipment were the most imported goods from China in 2012, led by computers.