Fields succeeded Alan Mulally as president and CEO of the No. 2 U.S. automaker in 2014. He was ousted in 2017 and replaced by Jim Hackett.
Hertz Corp., a subsidiary of Hertz Global Holdings, operates the Hertz, Thrifty, and Dollar rental car brands.
The parent company’s shares were up nearly 10 percent in mid-day trade.
Fields joined the Hertz board of directors in June. He also is a member of Qualcomm’s board and is a senior advisor to TPG Capital.
At Hertz, Fields succeeds Paul Stone, who becomes president and chief operations officer, the company said.
In May, Hertz said a group of investors including Knighthead Capital Management, Certares Opportunities, and Apollo Capital Management would fund the company’s exit from Chapter 11 bankruptcy.
The 103-year-old rental car company was once owned by General Motors, which resold it to previous owner John Hertz in 1953. Subsequent owners included RCA, United Airlines parent UAL Corp., and Ford, which sold the business in 2005 to private equity firm Clayton, Dubilier & Rice.
By Paul Lienert