One of Birmingham's best-known business figures has collapsed and died while in training on his bike for an Ironman triathlon.

David Bucknall, aged 76, a "workaholic" and fitness fanatic who was still playing for Moseley Rugby Club's first team in his 40s, died yesterday morning after falling from his bike in the Warwickshire countryside.

He had enjoyed a hugely successful business career in the West Midlands, retiring in 2012 after more than 50 years at the helm at property and construction practice Rider Levett Bucknall.

Mr Bucknall project-managed the construction of Birmingham's Symphony Hall, International Convention Centre and National Indoor Arena.

He also cost-managed the restoration of Windsor Castle after the 1992 fire and project-managed the building of the Telecom Tower in Kuala Lumpur.

Long-time friend and well-known TV broadcaster Gary Newbon said: "I am totally shocked. David was the fittest guy out as well as a very, very successful businessman.

"He had time for everyone, a hugely popular and respected bloke. He was one of my closest friends - we always spent Christmas together with our families.

"He was a workaholic, up early and gone. He worked his socks off every day of his life. He ran marathons and was really fit.

"I remember staying with him and we were the last to bed at 2am and by the time I had got up, he had run six miles."

His daughter Julia said: "He was out on his bike training for an Ironman event when he keeled over.

"He was a sports nut. He played for Moseley first team for over 25 years, he played for Staffordshire at rugby, he had run 14 marathons, cycled from Berlin to Paris and from Land's End to John O'Groats.

"He was also a Wolves season-ticket holder and had followed the club for around 70 years."

Ann Bentley, global director at Rider Levett Bucknall, said on behalf of the company: "It was with great sadness that we learned of David's untimely death.

"There have been a handful of personalities within the property and construction industry that have inspired change and innovation but none as influential, pioneering and dynamic as David Bucknall.

"It was an honour and a privilege to work with him both on a professional and personal basis. Our thoughts are with his family at this difficult time, as well as our staff, for many of whom he remained a friend and mentor."

Mr Bucknall was awarded an OBE for services to the construction industry in the New Year's Honours List in December 2012.

The son of Charles Bucknall, who founded Bucknall Austin in 1947, he joined the firm in 1961 and took it from a small local quantity surveyors' practice to flotation on the London Stock Exchange.

He played a pivotal role in the 2007 merger which created the global firm Rider Levett Bucknall, bringing together Australian firm Rider Hunt, Hong Kong-based Levett and Bailey and Bucknall Austin. The group now employs 3,500 people across more than 120 offices worldwide.

Mr Bucknall, who lived near Stratford-upon-Avon, leaves a widow Moya, two daughters Julia and Lucy, four grandchildren George, Tashi, Gabriel and Alice Maude and sister Margaret. Funeral arrangements are yet to be announced.