In the surest sign yet that the runaway train of the property market isn't just slowing, it's grinding to a slow halt, house sales around the country in March slumped to less than half the number at the same time last year.

The Real Estate Institute of New Zealand (REINZ) is blaming everything from lack of consumer confidence, to the earliest Easter in years, to the Ides of March for the unprecedented drop - down from nearly 11,000 sales in March last year to only 5129 last month.

March sales were even lower than in January, when house-hunters are usually lying on beaches rather than looking for bargains.

Yet, REINZ points out there has been a "perverse increase" in the national median selling price - up from $337,500 in February to $349,000 last month, though it concedes that the small number of sales is "skewing" that impression.

And year on year prices are dropping in many centres. Auckland's median sales price dropped from $443,000 in March last year to $437,500 last month. REINZ president Murray Cleland said that with only four out of 12 regions showing rising median prices, the figures could not obscure the fact that prices were weakening.

"Add to that the likelihood of a growing number of properties coming on the market either through bank-forced sales, or through the collapse of property investment schemes, which will put more pressure on the market," said Cleland.

The median number of days taken to sell nationally has improved from 50 in February to 40 in March - but it is still taking longer than the 27 days in March a year ago.

Homes in every region in the country are taking much longer to sell. Northland homes are the slowest moving, taking an average of two months, compared with 45 days a year ago. Auckland homes aren't flying off the books either, taking 36 days, compared with 27 in March last year.

All but three areas in the Auckland region show falling prices, compared with last March, although prices in Auckland City, Franklin and Rodney have risen slightly.

But sales volumes have plummeted across the region. In North Shore, 269 houses sold last month, compared with 683 at the same time last year. In Papakura sales fell from 140 to just 46.

Andrew King, vice-president of the New Zealand Property Investors Federation, said March was traditionally a good month for sales, but the fall in volume had not come as a surprise.

King said there had been a large increase in the number of property listings, with people feeling it was their last chance to sell for a decent price. Mortgagee sales were also on the rise.