Both Foxtons and Countrywide are forecast to announce sharp falls in profits this week as they announce their annual results for last year, according to a report in the Mail on Sunday.
Foxtons is tipped to reveal a fall in profits from £43m in 2015 to £25m last year.
According to broker Peel Hunt, Countrywide will say profits fell from £86m to £56m.
LSL is also due to announce its results this week.
All three have previously delivered warnings on profits.