The contractor has lowered its forecast revenue to $A1.2 billion from $1.3 billion, not accounting for any new contracts won.

NRW said it now expected growth to be 15% on the 2012 financial year and said the change in the FMG contract would have no impact on the 2014 financial year.

Current civil works for FMG at Anderson Point and the Solomon spur would run through to completion.

The company said it was disappointed, but was in a position to mitigate any impacts and said it was working with FMG to manage an orderly transition of staff.

NRW had been in a trading halt since FMG made the announcement on Tuesday morning in the wake of low iron ore prices, now trading at below $US90 per tonne.

Meanwhile, Calibre Group and Macmahon Holdings, which are both working on FMG rail projects, said there would be no impact.

NRW shares fell A4c to $2.19 this morning.