London-focused real estate agent Foxtons Group said the property market had seen record low sales volumes in the first quarter, hurting revenue as ongoing Brexit uncertainty hurt consumer confidence.
The warning comes months after one of Britain's best-known property names scrapped its dividend for 2018.
It also reported a fall in core earnings, hurt by weaker sales and higher costs in a tough market.
London's previously strong property market has been sluggish in many areas over the past year hit by the uncertainty generated by Britain's decision to leave the European Union and a rise in stamp duty property tax.
Traditional agents like Foxtons have also been challenged by nimble new internet-driven players like Purplebricks.
Foxtons' group revenue dipped to £23.8m for the quarter ended March 31, compared with £24.5m a year earlier. The company said this was in line with its expectations.
The brand had already said in February that it expected trading to remain challenging in 2019 ahead of Britain's impending exit from the European Union.