Charles Michael Harper was born on Sept. 26, 1927, in Lansing, Mich. His father, Charles, was a hearing aid salesman, and his mother, the former Alma Anna Michel, helped her husband in that business. Mr. Harper was an undergraduate at Purdue University and got an M.B.A. at the University of Chicago. He married Joan Bruggema in 1950. She died in 1999.
In the 1970s and 1980s he transformed a faltering food company called ConAgra into a global giant to rival Kraft and Kellogg, and whose own health issues inspired the creation of the brand Healthy Choice. At ConAgra, Mr. Harper oversaw one of the most notable turnarounds in postwar corporate America. He joined ConAgra in 1974 after 20 years at Pillsbury, another food company. ConAgra at the time was suffering losses that had put it close to bankruptcy. Mr. Harper, who was known as Mike and wore short-sleeved shirts in the dead of winter, became the chief executive in 1976 and was in that post until 1992.
Mr. Harper became chief executive of RJR Nabisco in 1993. Mr. Kravis hoped that his skills would revive the company. But Mr. Harper struggled, in part because of challenges facing the cigarette business, and he left RJR Nabisco in 1996.
In addition to his daughter Kathleen Wenngatz, Mr. Harper is survived by two other daughters, Elizabeth Murphy and Carolyn Harper; a son, Charles Jr., a neurologist at the Mayo Clinic; 11 grandchildren and 11 great-grandchildren.