The ruling is the latest blow for the OFT which has already been ordered by the Competitions Appeal Tribunal to cut fines following appeals by contractors.
Nine firms will now have a portion of their appeal costs paid by the OFT following a ruling by the tribunal on Friday.
The firm awarded costs last week are:
Kier: £200,000
Ballast: £200,000
Bowmer: £150,000
Corringway: £170,000
Thomas Vale: £142,129.24
Sisk: £170,000
Seddon £45,642.35
Interclass £31,374.96
Tomlinson £79,872.80
Apollo £168,402.81
Galliford Try £160,000.