When Mr. Maxwell took the helm in 1984, Philip Morris had already started to diversify its business away from tobacco, buying the Miller Brewing Company in 1969 and 7-Up in 1978. But those acquisitions were meager compared with the deals Mr. Maxwell would clinch during his seven years as chairman and chief executive at the company’s New York headquarters. Moving with a swiftness that became Mr. Maxwell’s trademark, Philip Morris paid $5.7 billion for General Foods, the manufacturer of Jell-O, Birds Eye frozen foods and Kool-Aid, in 1985. Three years later the company acquired Kraft, the maker of dairy and other food products, for $13.1 billion. Since Mr. Maxwell’s departure in 1991, Philip Morris has gone in the opposite direction, dismantling its business — and his legacy — to again focus its efforts on tobacco. In 2002, the company sold Miller to South African Breweries. The next year, Philip Morris changed its name to the Altria Group. Its business now includes cigarettes, e-cigarette products and wine. His father, Alexander Maxwell, headed a British tobacco importing company and served as Britain’s tobacco controller during World War II. In the early 1950s, after studying history at Cambridge and serving in the Royal Air Force, Mr. Maxwell traveled to the United States as a tour agent with Thomas Cook & Sons, the British travel company. But he took a job at Philip Morris after his fiancée, Georgene Mathewson, insisted he get a better-paying job. He rose quickly through Philip Morris’s ranks, leading the company’s international division before leapfrogging several candidates to the chief executive spot.Mr. Maxwell’s daughter, Mrs. Russell, said that he rarely smoked in private, and that he had completely stopped about a decade ago. In addition to Mrs. Russell, Mr. Maxwell, a longtime resident of Brooklyn Heights, is survived by another daughter, Robin Maxwell; four grandchildren; and his sister, Hilary Harding. His wife of 58 years, Georgene, died last year.