The London Stock Exchange says a man fell from an upper floor balcony at the site.
The City of London police say they are investigating the circumstances after being called to the central London exchange Tuesday morning. The incident is not being treated as suspicious.
The stock exchange described the person as a “London Stock Exchange Group colleague.” It said in statement that its thoughts and condolences are with the family.
A spokesman for London Ambulance Service says they were called at 9.56 a.m. (0856 GMT) to reports of a person fallen from a height at Paternoster Square.
The service says it sent an incident response officer, an advanced paramedic, an ambulance crew and a motorbike responder, but that the “patient was dead at the scene.”