Green worked for Kier for over 20 years and was second in command in the procurement team after director Kevan Jepps.
Nigel Brook, Kier executive director construction and infrastructure services, said: “I have had the privilege of working with Mike for a number of years and on behalf of us all here at Kier I’d like to send our condolences to his wife and family at this very sad time, and let them know that they are in our thoughts.
“We have all been affected by this extremely sad news and we will remember Mike as a well-respected colleague, a wonderful friend and a great guy to be around. He will be missed by everyone.”
Another former colleague added: “I had the privilege of working with Mike and he was one of the nicest guys you could ever meet.”