More than 100 construction firms, including leading Shropshire builders Galliers, were today accused of “bid-rigging” by competition watchdogs following a four-year investigation.

Shrewsbury-based Frank Galliers Ltd was named by the Office of Fair Trading as one of 112 firms allegedly involved in cartel-type activity when bidding for contracts worth £3 billion.

The company today “vehemently” denied any wrongdoing.

The OFT inquiry spans 240 cases where firms have allegedly colluded to inflate prices during a tender process, covering both the private and public sector.

Construction giants Balfour Beatty and Carillion are on the list of firms being investigated as well as Leominster firm J Harper & Sons.

John Fingleton, OFT chief executive, said: “This investigation, together with the OFT’s previous decisions in the roofing sector, will hopefully send out a strong message to the construction industry about the seriousness with which we view suspected anti-competitive behaviour. Businesses have no excuses for not knowing and abiding by the law.”

Bicton Heath-based Frank Galliers, a family business which became part of Pan-Atlanta Developments Ltd in 2004, today vehemently denied any allegations of “corruption or profiteering” from a practice it claimed had been widespread in the industry.

The firm’s solicitor, Roland Taylor, said: “There has been in the past a culture of cover pricing in the industry. Cover pricing has nothing to do with the allegations made by the OFT which are vehemently denied by Galliers of profiteering, backhanders or the like.

“Cover pricing relates to pressure within the construction industry to remain on tender lists. There was a practice that companies wanting to remain on the tender list but not wishing to have that particular work would liaise with other companies, get a ball park figure and make a bid so ridiculously high that there was no chance of them getting the work.

“It was nothing to do with colluding together and if you didn’t tender you would be taken off the list. There was no exchange of money.”

He said the OFT investigation relating to Frank Galliers concerned three incidents, two relating to the time prior to the current ownership and one relating to a short time after the new owners took over. It is not known whether any of the three involved projects in Shropshire.

J Harper company secretary Vikki Overton said: “We are considering the matter . . . and have co-operated fully with the OFT.”