The firm said Peter Cleary passed away suddenly yesterday morning.
An internal statement sent around the company said: "It is with great sadness that we have to announce the sudden death of Peter Cleary, who died on his way to work yesterday.
"Peter worked for Land Securities for 20 years and was a popular and respected figure across the industry.
"He will be sadly missed by all his colleagues in the Retail team and across the business. Our thoughts are with his wife, Mary, and family at this sad time."