The BNZ-BusinessNZ performance of services index fell to a seasonally adjusted 51.9 in December, down one point from November and the lowest since September 2012. The long-term average is 54.4, with a reading above 50 indicating expansion.
"It's not the end of the world but there were some downward revisions as well – just not a good story," said Mike Shirley, a dealer at Kiwibank.
Reports of more than 200 cases of a coronavirus - mostly in China - possibly had some impact on the currency at the margin, Shirley said. The virus is from the same family as the Severe Acute Respiratory Syndrome, or SARS, virus that caused more than 700 deaths in 2003.
"That could have an impact on tourism" if China decided to shut down external travel as a result, he said.
The virus originated in animals but can be spread person to person.
Most of the cases have been people who visited an animal and seafood market in Wuhan, a city about 700 miles south of Beijing, but some had not and there have been four cases outside China in Thailand, South Korea and Japan.
"There's not a lot of love to take the kiwi higher but not enough lack of love to take it significantly below 66," Shirley said.
The New Zealand dollar was trading at 96.23 Australian cents from 96.19 cents yesterday, at 50.77 British pence from 50.91, at 59.53 euro cents from 59.67, at 72.64 yen from 72.95 and at 4.5533 Chinese yuan from 4.5343.
The two-year swap rate rose to a bid price of 1.2088 per cent from 1.1875 yesterday, while 10-year swaps climbed to 1.6575 per cent from 1.6475.