Median rents are on the rise in the Western Australian capital, according to new figures from the state's real estate institute.

The median rent in Perth climbed by $10 over the three months to January, making the average weekly rent $380, according to the Real Estate Institute of Western Australia (REIWA).

Vacancy rates remained stable at 3.4%, but REIWA president Alan Bourke suggested that these could fall in the coming months.

"The March quarter is traditionally a time when vacancy rates tighten and rents increase due to seasonal factors, such as pressure from university students," said Bourke.

He added that it's unclear whether the upwards pressure on rents would continue, saying that demand for rental properties would be "driven by the broader economy and the availability of jobs".

The increase in median rent is good news for WA investors, who have suffered from median house price falls and a slow market in recent months. REIWA's review of the last quarter of 2010 revealed that the Perth median house price dropped back to $480,000 – the same as it was at the end of 2007 – and that sales turnover was also 30% below Perth's 15-year average for both houses and units. REIWA figures also suggest that 68% of vendors have dropped asking prices to secure a deal.