Countrywide has warned that 2016 EBITDA will be at the lower end of market expectations.
And it says "this challenging environment underlines the importance of our focus on efficiency and productivity and the shift to our multi-channel model which we expect to yield significant benefit to our performance".
An update says: "As expected when we reported our Interim results, transactional activity in the residential property market has remained challenged. A combination of changes in stamp duty and the EU referendum in June means transaction levels are currently running significantly below 2015. Bank of England mortgage approvals in Q3 2016 were 12% below last year. We now expect transaction volumes for 2016 to be 6% down on 2015 and while too early to say definitively, it is likely that the level of market transactions in 2017 will be lower than 2016.
"The lettings market was affected by the rush to beat the changes in stamp duty at the end of Q1, resulting in a larger than usual supply of rental properties. Stock has increased more than tenant numbers, meaning more choice for tenants slowing rental growth, with rents falling in some areas. Overall though tenant numbers have increased slightly compared to last year and we expect the slowdown in the sales market to support the growth in the size of the rental market in the medium term."
Chief executive Alison Platt said: "We have made good progress this year despite tough market conditions since the EU referendum, particularly pleasing is our growth in market share in both Sales and Lettings based on available market data up to July. In addition, these results in our Lettings, Mortgage and Professional Service businesses underline the importance of the breadth of the group and the focus we have placed on keeping the customers we win and continuing to serve them.
"In light of the chancellor's announcement yesterday regarding letting agents' fees, we look forward to working with the Government through this consultation process. The results of our digital sales pilot and the roll out of Fixflo in Lettings signal strong steps towards building our multi-channel network across the UK. Our work to ensure we have fewer, better brands and branches continues at pace."