AMEC boss Sir Peter Mason expects the firm to begin posting clean sets of results soon, after profits were once again hammered by exceptional items last week.
In the six months to June the firm racked up nearly £80 million in exceptionals. Pre-tax profits collapsed by £76 million to leave the figures nearly £58 million in the red.
Presiding over his last set of results, Sir Peter, who is stepping down from the chief executive post after a decade in charge, defended his record, which has seen Amec's recent figures dominated by the blight of exceptional items.
He said: 'When I arrived there were a very large number of businesses collected over 50 years. I've spent 10 years trying to rationalise the portfolio, which is just about done.
'The net position of exceptionals is a credit of £100 million. I don't see a lot to be done next year.'
Amec will decide by the end of the year whether it will sell off its construction-related operations, which include M&E services, property development, wind energy and PFI.
The loss-making UK building and civil engineering business is being restructured under new boss John Moss. Sir Peter added: 'If we don't sell it we want it performing.'
Sir Peter said he should have begun the strategy to separate out its construction businesses at least 12 months before the firm embarked on the process last November.
He said: 'We were seen as too complicated by the City and I should have given up trying to persuade the City a year or two earlier.'
New boss Samir Brikho will take charge of a company that will focus on its core energy and process markets.
Amec has lodged a claim for compensation with the Department of Health after it spent £7 million on wasted bid costs when a PFI hospital scheme on which it was preferred bidder was scrapped in June.
Plans for Colchester General Hospital were ditched because of funding issues and Sir Peter pledged to get the money back.
He said: 'It is extremely unlikely that we will not get our £7 million.'
Turnover at the firm in the half year went up 20 per cent to £1.7 billion.