Lockhart founded New River with Allan Lockhart and Mark Davies in 2009 and played a major role in establishing the group as a leading real estate investment trust with a portfolio valued at £1.2bn before stepping down as chief executive in 2018.
In 2014, he was also a co-founder of Hawthorn Leisure, which now owns and manages more than 700 leased, tenanted and operator managed pubs across the UK in community, town and city centre locations.
A statement from Hawthorn Leisure said: “David was an entrepreneur, family man and inspirational leader. He was highly respected across the industry, and in a long and varied career set up three successful businesses.”
“In addition to exceptional business acumen, David had a great passion for property and people.
“He firmly put people at the core of everything he did and was very generous with his time, developing and shaping so many careers and a legacy culture that the company and its stakeholders will always benefit from.
“David will be greatly missed by many of his current and former colleagues, close advisors and a wide range of industry contacts, a large number of whom became close personal friends over the years.
Long and distinguished career
“David was a close personal friend and mentor, and we are deeply saddened by this news,” Hawthorn Leisure's CEO Mark Davies said. “The thoughts of everyone at Hawthorn are with David's family at this difficult time.
“As chairman of Hawthorn, David provided invaluable counsel and advice to our board, and we benefited hugely from his long and distinguished career in business.
“He and I worked tirelessly with our brilliant team to help create a market leading community pub company.
"David was a brilliant entrepreneur and will be remembered for his warmth, good humour, wisdom and sharp intellect and we will all miss him dearly.”