The consulting engineer expects to make a one-off charge of around £23m to cover a redundancy programme that has slashed the headcount by more than 2,000 since January last year.
The firm blamed the slide on the challenging business environment and its decision to “take a more cautious view of the final settlement of a number of current project claims”.
City analysts had expected pre-tax profits of £35m.
In a trading update ahead of its results announcement in two weeks, Mouchel said net bank borrowings were better than expected at £83.5m.
“Discussions are already underway with our banks on the refinancing of our existing loan facilities.
“We are confident that the refinancing will be successfully completed by the time of our interim results announcement,” said the company statement.
The big cuts programme is expected to deliver cost savings in excess of £25m, better than previously expected.
The Group’s order book and pipeline both remain at around £2bn