He joined the agency in 1961 and was known as a tough negotiator. Under his watch, Leo Burnett grew into the country’s biggest buyer of print, radio and broadcast advertising with a client roster that included McDonald’s Corp., United Airlines and Miller Brewing Co.
Mr. Hadlock advocated the growing importance of media in the marketing mix. Indeed, Burnett’s media department broke off into its own in the mid-1990s as Starcom. It is now part of the country’s biggest media agency, Starcom MediaVest. Jack Klues, the CEO of Starcom MediaVest, was hired by Mr. Hadlock.
Mr. Hadlock's direct style in dealing with people --"you knew exactly where you stood" -- had an influence on the management style of Mr. Klues and others at the media agency, Mr. Klues said. "I hope I'm as direct."
Mr. Klues credited Mr. Hadlock for being forward-thinking in embracing emerging media. Under his stead, Burnett was a pioneer in syndication and cable. "He saw [TV] on a much broader spectrum than other peers of his day," he said.
Leo Burnett and Starcom MediaVest are part of Publicis Groupe.
William Lynch, a former CEO of Leo Burnett and a contemporary of Mr. Hadlock, said, "He was really the heart and soul of the media department." Mr. Lynch credited Mr. Hadlock with such innovations as bundling clients' media dollars together to negotiate for better rates and segmenting buys according to target groups.
Mr. Hadlock, who was in his early 70s, retired in April 1993 and was succeeded by Richard Hobbs. He is survived by his wife.