 Trained as an electrical engineer, after his older brother Aird decided to take over permanent management of the family-owned Ogilvy department store in Montreal, Nesbitt joined the family's securities business.On the death of his father in 1954, he became head of the brokerage firm and took over the presidency of the Nesbitt Thomson holding company, Power Corporation of Canada.Under his guidance, Nesbitt Thomson expanded across Canada, and into the United States and Europe.