PRE-TAX profits at privately-owned building contractor Sisk Group more than doubled by 110pc to ?85.4m last year, according to full year results published yesterday.
Group operating profit increased by 55pc to ?68.5m.
Turnover increased by 31pc to just over ?1.5bn in a year when construction costs rose by 5pc.
Bernard O'Connell, Sisk's executive chairman - construction, said that activity growth of approximately 25pc was well spread across the group's civil engineering and contracting activities.
Of the 2005 turnover, ?1bn came from John Sisk & Son in Ireland, which completed projects like the G Hotel in Galway and the New School of Music in Cork.
Sisk also has an Irish civil engineering division which is heading for turnover of ?100m by 2007 in high-profile public private partnerships such as the Ashbourne N2 to M50 motorway and the Limerick Tunnel.
John Sisk & Son (UK), the UK division, accounted for ?380m in turnover last year from commercial, retail and residental projects.
Sisk also built a new distribution warehouse and corporate offices for Tesco in Coventry.
Mr O'Connell said that construction activity has been maintained at a high level particularly in Ireland in projects for the water, bio-pharma, residential, healthcare and retail industries.
"We certainly will not see an increase of 31pc in the current year, but commercial, retail and residential are quite strong while manufacturing is in decline," Mr O'Connell said.
The group is wholly-owned by the fourth generation of the Sisk family to be involved in construction.
Sisk company said it had diversified into a number of non-construction businesses and was seeking 'high-quality' acquisition opportunities.
Sisk has diversified into other businesses such as healthcare equipment, medical devices and property investment. It also owns electrical appliances distributor Origo.
Liam Nagle, who heads the trading, healthcare and investment business, said two acquisitions have been made in 2006 - MED Surgical and Cardiac Services - and that future acquisitions will be made seeking synergies with existing Sisk operations.
Korine Property Partners, the property investment and development arm of the group, disposed of ten commercial properties from its portfolio in Ireland and England in 2005.