Unveiling marginally improved results for the first half of the year, chief executive David Lawther, said the firm had seen a significant increase fit-out activity in the capital and data centre work overseas.

He added that ISG was now investing in increasing capacity, knowledge and skills across these businesses.

But ISG’s construction division continued to struggle, only just keeping in the black with a £100,000 profit booked on turnover down 17% at £234m.

Across the group, pre-tax profits crept up £200,000 to £2.4m on turnover ahead 8% to £708m in the six-months to December.

Lawther said the outlook for the second half was much better with the order book up 26% to just under £1bn.

Lawther said: “The London office fit-out market has made a strong recovery with revenue increasing by 40% as a result of the return of large-scale projects.

“We are now working on six major schemes with a combined value in excess of £300m.

This includes a £32m project to revamp retail conglomerate Arcadia’s headquarters in Mayfair, a £50m+ fit out for the tenant of a 17-floor office building near London Bridge station.

ISG revealed it spent £1.4m restructuring the construction division into three regions.

“Our UK Construction business has invested in its planned restructuring and is starting to see an improvement in its pipeline.”

Lawther said ISG had seen a marked improvement in consumer confidence, which has delivered several large projects, like the Exhibition Centre Liverpool and a £20m+ contract to build the UK headquarters for The Phoenix Partnership in Leeds.

But he warned: “We anticipate that margins will continue to remain low in 2014 as we work out projects secured during tougher market conditions in the preceding periods.”

Net cash improved from £25m to £33m.