Progressive Corp. Chairman Peter B. Lewis, the billionaire who turned a company founded by his father into one of the largest U.S. auto insurers, has died. He was 80.

Lewis died Saturday at his home in Coconut Grove, Florida, after suffering a heart attack, said his philanthropic adviser, Jennifer Frutchy. Lewis, Progressive’s chief executive officer for 35 years, built the firm on transparency, reporting results monthly instead of quarterly. He also made it the first insurer to publicly compare its rates to those of competitors and ask for consumer input on pricing, said CEO Glenn Renwick.

“Transparency was always something that Peter was very forthright on,” Renwick said today in a telephone interview. “Even in his own philanthropy, he was never shy to say what his thinking was.”

Lewis was non-executive chairman of Mayfield Village, Ohio- based Progressive, co-founded by his father Joe Lewis in 1937, and was succeeded by Renwick as CEO in 2000, according to the firm’s website. The billionaire was among philanthropists who joined Warren Buffett and Bill and Melinda Gates’s initiative to pledge at least half of their wealth to charity.

Later in his life he pushed to legalize marijuana. Lewis supported efforts to give patients in the U.S. access to marijuana, and used cannabis to relieve pain after the amputation of his lower leg. He donated more than $2 million to help pass Initiative 502 last year in Washington state, which legalized possession and consumption of the weed for recreation use, said Alison Holcomb, the campaign director for the group that supported the ballot measure.

‘Incredibly Grateful’

“We were, of course, incredibly grateful for Mr. Lewis’s significant contributions that made Initiative 502 possible,” Holcomb said in a phone interview. “We’re very hopeful that others will follow in the example that he set.”

Lewis was Progressive’s biggest shareholder, with a stake valued at about $1.2 billion, data compiled by Bloomberg show. The Princeton University graduate, who was among the school’s biggest benefactors, began his career at Progressive in 1955 and transformed the company into what is now the fourth-biggest U.S. auto insurer.

Progressive gained market share partly by selling policies online and by phone, and is benefiting as drivers rely less on insurance agents. The insurer has sought an edge through data, using metrics such as credit scores to help determine rates. More recently, it began evaluating motorists’ habits through devices in their vehicles and said it will profit by licensing the technology to other companies.

Zuckerberg, Ellison

Buffett, 83, the chairman and CEO of Berkshire Hathaway Inc., created the Giving Pledge with the Gateses in 2010 to boost philanthropy among the world’s richest people. The effort has drawn 92 commitments, including from Facebook Inc. founder Mark Zuckerberg, former Citigroup Inc. CEO Sanford “Sandy” Weill and Oracle Corp. CEO Larry Ellison.

Lewis hired Frutchy to keep her husband, Ed Ford, then the chief actuary, at the company, she said. Frutchy worked for Lewis for 27 years, sticking with him even after her husband left the company 20 years ago.

“He was larger than life in personality and demeanor in every way,” she said. “He was a great person to work with and learn from.”

Frutchy said Lewis is survived by a brother, Daniel, three children and five grandchildren.

–With assistance from Noah Buhayar in New York and Alex Cuadros in Sao Paulo. Editor: Peter Eichenbaum