About 42% more surveyors reported that rents rose rather than fell in the three months to April, the Royal Institution of Chartered Surveyors said.
Rents in London and the South East rose faster than in any other region in the UK. Some 33% more surveyors expect rents to rise rather than fall by the end of 2011.
Expectations for rental prices were highest in London, followed by the Midlands, the South East and the North.
James Scott-Lee, spokesman for RICS, said: “Although we are beginning to see more mortgages aimed at first-time buyers, many potential homeowners are still restricted from getting a foot on the property ladder, leading to increased demand in an already oversubscribed rental market.
“There has been a small uplift in supply, but the imbalance between demand and availability can only mean rents will continue to rise.”
