Auckland house sales and prices fell last month as the country's biggest city continued to enjoy a glut of properties on the block, realtor Barfoot & Thompson says.

The number of houses sold in Auckland fell 24 per cent to 721 and the median sale price slipped 1.2 per cent to $840,000 in December, Barfoot said in a statement. The median price was up 5 per cent from December 2015, while the volume of sales was down 9.4 per cent.

"While prices definitely eased there was certainly no suggestion that current prices are under any great downward pressure and normal sales numbers are being achieved," said managing director Peter Thompson.

The slowdown in Auckland's housing market came as Barfoot, the city's biggest realtor, had 3,270 properties on its books at the end of the month, up 35 per cent from a year earlier, and the biggest available stock at the end of the year for four years. Barfoot had 776 new listings in December, less than half than in November, though still up 2.5 per cent from a year earlier.


ASB Bank economist Kim Mundy said those rising inventory levels appear "to be taking some of the heat out of Auckland house price growth", though they're still near historical lows which should keep a floor on prices.

New Zealand's housing market has posed problems for policy makers with rapid price gains seen as crowding out first home buyers who are also stifled in their ability to obtain credit by Reserve Bank-imposed restrictions on highly-leveraged mortgages. House prices inflation cooled through the latter part of 2016 as banks tightened up their lending policies, and may continue to do so with interest rates now expected to start increasing this year.

Barfoot's average sale price of $913,709 was down 2.1 per cent from November, its second monthly decline, though still up 5.1 per cent from a year earlier.

Thompson said the monthly dip in prices was similar to what happened in December 2015, when the average sales price slipped 0.8 per cent, the median price rose 0.8 per cent, and the volume of sales fell 19 per cent.

"December's modest price retreat is similar to what occurred last December and it took until March for the upward price trend to re-appear," he said.

Sales of million dollar properties accounted for 39.1 per cent of turnover in December compared to 34.9 per cent a year earlier, while sub-$500,000 houses accounted for 7.2 per cent, up from 5.5 per cent in December 2015.