Chief Executive Ian Tyler told analysts: “We will have to look at desisting from certain areas of the market.”
Areas under scrutiny include social housing and rail renewal work in the UK plus rail operations in Europe.
Tyler said: “There will be a phase three restructuring that will be responsive to different market conditions.”
He added that the firm had been in a “constant state of cost cutting since 2010” and Balfour has shed 1,400 jobs globally this year.
Balfour’s “Phase Two” restructuring is currently underway which will see 650 UK construction jobs go and the closure of 35 regional offices.
The profit warning saw Balfour’s share price drop 9.78%.
The firm said: “We will take further action, both operationally and strategically where necessary, to mitigate any adverse impacts on our business.”