Support services group, Amey, is set to reveal details of a sweeping write-down plan later today.
The writedowns and provisions are expected to be at least £60m, consuming most of Amey's profits.
Acting finance director Eric Tracey said the write-downs were non-cash charges, and that a strong trading position should continue.
Amey is believed to expect the statement will provide shareholders with a clear view on its financial state.
Amey is expecting the provision in conjuntion with a deal with the Tube Lines consortium, will allow it to rengotiate its loan arrangements.
Its banks had to bail out Amey after the uncertainty over its finances made renewing a letter of credit for its £60m investment too expensive.
