Montpellier will hope that the appointment will end an unsettling 18 months for the firm, which saw former managing director Paul Sellars resign last year and the company pull out of a controversial animal research laboratory in Oxford after threats to shareholders from animal rights activists.
He was also the last chief executive of Laing Construction, which was plagued with nearly £100 million in losses following disasters on the Cardiff Millennium Stadium and National Physical Laboratory PFI deal in Teddington. He was at the helm when Laing's board sold the company to Ray O'Rourke for £1 in 2001.
Since leaving HBG he was also linked with senior positions at Wates and Mowlem.
Mr Harrison commented: 'I am delighted that Brian is joining Montpellier. With his extensive industry knowledge and experience I am confident the business will now take maximum advantage of the strong markets available.'