The move has raised speculation about a buyout of Miller Group, which also carries out house building and property development work.
The Aligned Shareholder Group, made up of members of the Miller family, including former chairman James Miller, has issued a statement in which it said it was considering selling up. The group owns 60 per cent of the company’s shares.
It said it had commissioned “a strategic review to evaluate options”, which “may include a disposal”.
A Miller spokeswoman said: “The group is not for sale.”
Current chief executive Keith Miller is the only family member still employed by the company but is not part of the Aligned Shareholder Group. He is believed to own around 17 per cent of the shares.
In 2006, Miller raised pre-tax profits 43 per cent to £10.6 million while turnover went up a third to £342 million.