Complex sentence: In 1977 Sassoon began a career in finance at Thomson McLintock & Company, and in 1985 joined S.G. Warburg & Co. (later UBS Warburg).
Split into simpler sentences: In 1977 Sassoon began his career in finance at Thomson McLintock & Company. In 1985, he joined S.G. Warburg & Co. (later UBS Warburg).