The cause of death was pancreatic cancer.
Best known for his stint as CEO of Braniff, which he joined in 1965, Mr. Lawrence transformed the regional carrier into the nation's eighth-largest airline. Key to the turnaround's success was a marketing and image campaign, the "End of the Plain Plane," created by advertising executive Mary Wells, who later married Mr. Lawrence in 1967.
Born in Perkins, Okla., Mr. Lawrence served in the Air Force during World War II and began working in commercial aviation in 1946. Almost two decades later, after holding jobs at airlines including Continental and Pioneer, he joined Braniff.
On Ms. Wells' advice, Mr. Lawrence and Braniff's marketing team embarked on a colorful campaign that included painting jet planes in bright colors, sometimes by up-and-coming artists such as Alexander Calder, and dressing flight attendants in uniforms made from bold fabrics. By 1980, when Mr. Lawrence retired, Braniff had revenues of more than $1.5 billion.
After leaving the airline, Mr. Lawrence worked with Ms. Wells at her Manhattan agency, Wells, Rich, Greene. She sold the agency in 1990.
Mr. Lawrence is survived by his wife and children.