The operation will now focus on repeat business from existing clients to avoid fiercely competitive open tender work.
Construction margins continued to come under pressure but ISG said it remained on course to deliver a modest rise in turnover for the first six months of its financial year.
In a trading update for its agm the firm said: “We have seen particularly tough trading conditions in our East region where we are in the process of a reorganisation to reflect current market conditions.
“We have continued to focus the business on repeat customers and frameworks, which now account for 50% of our activity, reducing the dependence on the open-tender market.”
A 7% rise in group-wide orders to £761m and recovery of workloads in the south west has kept the business on track.
ISG picked up extra work from LOCOG for the Olympic park redevelopment and secured the £61m Centre Parcs development in Woburn, a £30m new warehousing project for Diageo in Scotland and a £40m Exhibition Centre in Liverpool in the second part of the year.
The fit-out business saw a big rise in activity in the first half, driven by a £100m+ data centre project for Santander in Leicester.
The firm has also been named as lead contractor on a £120m project for a global technology customer in the Nordics.
In the London, ISG’s fit-out arm has won a £23m project for a leading insurance broker, as well as being appointed as preferred bidder on a £25m project.