Unit rental prices have eased in Sydney and held steady in Melbourne but soared in Hobart and Canberra, new figures show.

The median rental price for units in Sydney dropped 0.9 per cent to $545 a week in the three months to December, 2017, while the median rental price for houses remained steady at $550 a week, according to online property group Domain’s latest quarterly rental report.

As for Melbourne, the median for units was steady at $400 a week while the weekly median for houses rose 5.3 per cent to $425.

Domain data scientist Dr Nicola Powell said if investor activity continued to decline in Sydney, it could tighten the rental market in 2018.

However, she said new apartments could provide renters with more choice in some pockets of Sydney as stock from off-the-plan sales comes onto the market.

Dr Powell said Melbourne’s soaring population will put pressure on rental prices.

She said Hobart had the highest growth rate in median house rental prices during the December quarter and its houses continued to provide the best gross rental yields for houses.

“Canberra and Hobart, two cities at opposite ends of the affordability spectrum, saw the greatest price growth,” Dr Powell said.

“Even though there’s a distinct gap in their median rental prices, it’s clear that tenants in both cities are facing a competitive rental market.”

Hobart was also the only capital city to reach double-digit annual growth in house and unit rental prices of 12.9 per cent and 13.3 per cent, respectively.

House rental prices increased 6.8 per cent over the quarter to $395 per week and unit prices lifted 6.3 per cent to $340 a week.

The median cost to rent a house in Canberra increased 5.9 per cent over the quarter to reach a new record of $540 per week, while median unit rental prices climbed 2.4 per cent to $430.

In other states, Brisbane and Perth’s median house and unit prices were steady, Adelaide’s house rents rose 2.8 per cent while its unit prices were flat, and in Darwin house rents climbed 5.8 per cent and unit rental prices rose by 3.8 per cent.