Mr. Burson became one of the nation’s most celebrated P.R. men, a founder of the giant Burson-Marsteller agency who broke ground not only by enhancing corporate images but also by helping clients soften the blows of potentially ruinous crises. These included a Tylenol-tampering case that panicked Americans in 1982, and the 1984 toxic gas leak that killed thousands in Bhopal, India, considered the world’s worst industrial disaster. He died on Friday in Memphis, the city of his birth, where he had resided for the last six months. He was 98. Catherine Sullivan, a spokeswoman for his company, now known as Burson Cohn & Wolfe, said the cause was complications of a fall in November. He had lived for many years in Scarsdale, N.Y., and Manhattan before moving to Memphis in July to live with a niece. He died at Memphis Jewish Home & Rehab. In 1953, after seven years at his own agency, Mr. Burson and a Chicago advertising man, William A. Marsteller, agreed over a breakfast at the Plaza Hotel in Manhattan to team up and call the new agency Burson-Marsteller, with offices in New York and Chicago. Over the next 35 years it became one of the world’s largest and most successful public relations firms, rivaling Hill & Knowlton, as the industry evolved into mass marketing and global communications. Burson-Marsteller’s clients included Philip Morris, Merrill Lynch, Coca-Cola, Shell, ExxonMobil, General Motors, Dow Chemical, IBM, American Express and Citicorp. Burson-Marsteller also promoted trade and tourism in Romania and Argentina. Human rights advocates said the work supported brutal regimes in the 1960s and ’70s. Nigeria hired Burson-Marsteller in the late 1960s to counter allegations of genocide in Biafra, the breakaway state that was defeated and reabsorbed by Nigeria in 1970 after almost three years of civil war. He and his wife, Bette Burson, lived quietly for decades in Scarsdale. He had married Bette Ann Foster in 1947. (She was his office manager during the first five years of their marriage.) Ms. Burson died in 2010 at 85. Mr. Burson is survived by their sons, Scott and Mark; and five grandchildren.. In 1979, Burson-Marsteller was acquired by Young & Rubicam, the advertising agency, which was absorbed by the communications giant WPP Group in 2000. Mr. Burson remained as chief executive of Burson-Marsteller until 1989, when he became founder-chairman. Mr. Marsteller, who retired in 1979, died in 1987. Harold Burson was born in Memphis on Feb. 15, 1921, a son of English immigrants, Maurice and Esther (Bach) Burson. He graduated from high school at 15 and worked his way through the University of Mississippi writing articles, at 14 cents per column inch, for The Commercial Appeal in Memphis. After graduating from Ole Miss in 1940, he took a P.R. job with H.K. Ferguson, an engineering and construction company, which began building military installations as America went to war. Deferred from the draft for a time, he joined the Army in 1943, in the middle of World War II. He mustered out in 1946, landed in New York and became sole proprietor of Harold Burson Public Relations.