UK landlords own their properties for an average of 17 years before selling up, according to Countrywide's latest Lettings Index.
This is three years longer than the average homeowner and five years longer than in 2007, before the recession.
Countrywide says landlords have consistently sold less often than homeowners in every year during the last decade.
As the recovery from the recession took hold from 2011, the agency says the time landlords hold their investments has fallen. The average time between sales by landlords fell from 20 to 17 years between 2011 and 2015.
The Index says the 32% of properties owned by landlords have not been sold in the past 20 years.
“Most landlords consider property to be a long term investment. With landlords keeping their properties for 17 years on average, there is more stability in the sector than is widely recognised,” says Johnny Morris, Countrywide's newly-appointed research director.
“Long term investment decisions drive many landlords and two thirds of rented properties are owned without buy-to-let finance. This means many landlords are in a position to ride out short term market conditions in favour of expectations of future growth.”
Countrywide's Index, which analyses over 65,000 properties, calculates the average monthly rent of newly let homes at £937, a 1.1% monthly increase.
Regionally, the highest monthly increase was recorded in Central London, where the average monthly rent for a newly let property hit £2,583 in July, a monthly rise of 6.8%.
The most significant fall was recorded in Wales, where the average rent for a newly let property dropped by 2.3% to £685 a month.
Countrywide calculates the national average rent for occupied units at £846 a month, an annual rise of 2.7%.
Meanwhile, the figure for property renewals stood at £886, 5% higher than a year before.
“As landlords trade less often than homeowners, the growth of the private rented sector weighs down on the number of housing transactions. Less liquidity in the sales market can cause local market distortions and impact labour mobility,” adds Morris.
“As the private rented sector continues to grow it is likely we will see more owners searching for flexibility, blurring the lines between tenant and landlord by letting their properties while renting elsewhere.”
Last week, Your Move and Reeds Rains reported that average monthly rents in England and Wales hit a record high of £804 in July.