Clark, a father of four, was airlifted to the University Hospital of North Tees but died later.
Clark was a senior surveyor in the health and safety division of the Stockton-on-Tees office of the firm. He had been with the company 15 years.
The driver, Dave Matthews, 34, head of F&G's industrial maintenance division, broke both legs.
We are very close. The impact has been quite bad up here
F&G managing director Richard Hall
Michael Cook, one of the passengers, is now out of intensive care. He suffered internal injuries. Steve Humble, the other passenger, escaped with minor injuries. The two senior surveyors were taken to Middlesbrough general hospital.
F&G managing director Richard Hall expressed the shock felt by the firm, especially at its Stockton office. Hall said: "There's very much a family feel up here, we are very close. The impact has been quite bad."
Hall added: "There is some sense of relief in one regard that those who are injured are getting better. It is terrible for one to die but if you saw the car you wouldn't believe anyone could have got out of it alive."
The four were travelling back from a corporate sports event in Newcastle upon Tyne where they had been playing five-a-side football.