 When the war ended, he pursued a career in banking by joining Andre Istel and Company, a private investment banking firm owned by a friend of his father, and this gave him an opportunity to visit United States in 1946 for opening an office of his bank in New York.There, he met Marcel Schlumberger, one of the founders of the Schlumberger group, and on his invitation, Riboud joined Schlumberger as the founder's assistant in 1951.He continued in the company even after the death of Marcel Schlumberger in 1953 and rose in ranks to become the head of Europe operations and later, as the chief executive of the company in 1965.