Allen J. Bernstein, who greatly expanded the high-end Morton’s of Chicago steakhouse chain during his 17 years as chairman, applying what some in the industry called a Big Mac approach to filet mignon. Mr. Bernstein, who got into the food business selling hot dogs from a makeshift stand while in high school, opened the first Hardee’s fast-food restaurant on Long Island in 1968. He expanded that franchise to 14 outlets. By 1977 he had also founded Wenco Food Systems, which owned and operated 17 Wendy’s restaurants on Long Island, and in Queens and Manhattan. In 1988, with backing from Castle Harlan, a private equity firm, Mr. Bernstein started the Quantum Restaurant Group, which acquired Morton’s of Chicago within a year. At the time there were nine Morton’s steakhouses. When Mr. Bernstein retired in 2005 there were 69. Besides his wife of 27 years, the former Lori Waltzer, he is survived by a daughter, Stacey Stolar; a son, Adam; a sister, Helene Morrison; and one granddaughter. While studying for a degree in business administration at the University of Miami, from which he graduated in 1968, Mr. Bernstein wrote a senior thesis on fast-food franchising.