(CNN) -- The founder of the University of Phoenix, Dr. John G. Sperling, has died, according to a statement posted on the Apollo Education Group's website. He was 93.
The statement said Sperling passed away Friday at a hospital in the San Francisco Bay area. No cause was given.
"Dr. Sperling's vision, pioneering spirit and boundless resolve to improve the world through accessible higher education for working adult students provided a roadmap for families, nations and economies to evolve, advance, grow and prosper," wrote Apollo chairman and Sperling's son, Peter Sperling, and company Chief Executive Officer Greg Cappelli.
"Dr. Sperling's indomitable ideas and life's work served as a catalyst for innovations widely accepted as having made higher education more accessible to adult students," the statement read.
Sperling founded the Institute for Professional Development in 1972, followed by the University of Phoenix, a degree program aimed at working adults, in 1978. The for-profit university was one of the first to develop online degree programs.
The University of Phoenix is one of the largest private universities in the United States with more than a million students, alumni, faculty and employees, according to the Apollo Group, its parent company.
Sperling was born on January 9, 1921, in rural northwest Missouri. He served in the U.S. Army Air Corps and worked as a history professor.
Sperling is survived by his longtime companion, Joan Hawthorne; his former wife, Virginia Sperling; his son, Peter; daughter-in-law Stephanie and two grandchildren.
Chuck Johnston contributed to this report.