He will hand over the reins to his son Cathal O’Rourke, a graduate civil engineer who ran the Australian arm of the group for over a decade, and returned to the UK a year ago to become chief operating officer.

Laing O’Rourke founder Ray (left) hands the reins to son Cathal

Ray, aged 77, founded the business as a Essex-based formwork and concrete specialist, the year his son Cathal was born.

The firm entered the main contractor league in 2001 when Ray bought a struggling Laing Construction for a £1.

Since then he has been at the forefront of introducing modular and manufacturing approaches to construction.

Ray had previously planned to float the Laing O’Rourke business by 2024, with his succession part of that process.

While the group has grown steadily and achieved £3.6bn revenue last year, it year ran into problems with a costly legal dispute on a major project secured by the Australian business and operational losses in the UK. This saw it report a pre-tax loss of £288m last year postponing plans for a float.

Ray will continue to serve on the group board as a deputy chair, alongside his brother and partner Des.

He will also chair the board nomination committee, drive innovation in construction methods, and be available to the group CEO to meet with key customers, stakeholders and to provide mentoring and advice.

Ray said: “I am incredibly proud of our people and what we have achieved as a business.

“We have maintained a commitment to transform our industry, and our people are recognised for their ability to deliver complex engineering projects using advanced and sophisticated techniques across the globe.

“Cathal has enjoyed a successful career in our family business, spanning a quarter of a century and I have every confidence he will continue to lead our people well into the future, upholding the values and guiding principles that have been the foundation of our success.”

Cathal, aged 47, said he was “truly honoured to be trusted with the leadership of our business and our people.”

“Together we can continue to drive forward on our mission to transform our sector into a more sustainable and productive industry, embracing new and innovative ways of doing things, whilst at the same time, providing our people with safe, challenging and rewarding careers.”