The Competition Appeal Tribunal will confirm its decision next Tuesday on more than £15m worth of fines originally levied on Apollo, Galliford Try, GF Tomlinson, G&J Seddon, Interclass and Sol Construction.
Lawyers expect the fines to be cut in the wake of last week’s ruling which saw fines against the first six contractors who appealed against the OFT fines cut by £37m.
Contractors could also go after the OFT to recoup their legal fees following successful appeals.
The decision was a humiliating reverse for the competition watchdog which enjoyed initial success when fines of £130m were imposed on 103 contractors in 2009 following a masive probe into cover pricing.
The six firms who will learn the fate of their appeals next week are among a wave of 19 further contractors who appealed against the severity of the original decisions.
The fines originally imposed on the latest six were:
Galliford Try £8,333,329,
Apollo £2,150,536
Sol Construction £1,835,702
G&J Seddon £1,516,646
GF Tomlinson £1,269,270
Interclass £464,406.