A shortage of rental houses, paticularly in Christchurch is fuelling rent rises across the country, according to new figures from Trade Me.

The number of rentals available in the quake-hit region has plummeted 40 per cent in the last year - as the number of inquries to landlords has risen 42 per cent.

"When the first major earthquake struck (in September 2010), we saw supply begin to come under pressure, and the February 2011 earthquake exacerbated the shortage,'' said Brendon Skipper, head of Trade Me Property.

"Supply has continued to plummet, and the current level of rental inventory for the city is the lowest we have seen for years.


"It is a classic case of supply and demand, and is now flowing through to rent. We've seen the average asking rent go up 15 per cent in Christchurch, well ahead of the national increase of 4 per cent.''

The number of listings is down 7 per cent across the country, with bigger decreases in Wellington (12 percent) and Hamilton (9 percent).

Supply remains strong in student centres Dunedin (up 17 percent) and Palmerston North (up 13 percent).

The decrease in listings coincides with an average rent increase of 4 percent across New Zealand and 7 percent in Auckland.

Mr Skipper said although more listings were coming onto Trade Me Property, they were "not sticking around'' for long.

"So far this year, about a quarter of all listings in Auckland, Wellington and Christchurch were onsite for six days or less, which is great for landlords but another indicator of that strong tenant demand.''

He said there were signs pressure in the rental market was pushing prospective tenants to consider buying a house.

"Looking at our property for sale activity, we can see demand from potential buyers has increased by 13 per cent over the quarter, while sales inventory remains flat.''