Interserve flagged up problems with a contract to design, procure and install a gasification plant at a recycling and renewable energy centre in Glasgow more than a year ago when it warned that it had experienced problems with its supply chain, leading to delays.
It originally allocated £70m to pay for the project, before upping the amount to £160m.
More widely, the support services division has suffered this year amid extra costs associated with new regulations and a hiatus in Government procurement after the Brexit referendum.
The construction division, meanwhile, has struggled with generally tough market conditions and what Mr Ringrose last month described as “underperformance on a small number of contracts”.
But Andrew Nussey at Peel Hunt said he thought the troubles related to “various legacy issues, rather than market”. He said he had expected the construction division to break even this year after the earlier loss, but no longer thinks that is likely.
Russ Mould, analyst at AJ Bell, said the warning signs had been apparent in last month’s market update. “A cursory glance at August’s interim results would have given both investors and the new boss a clear indication of the risks and challenges that lay ahead,” he said.