Walter J. Zable, who founded and helped build one of San Diego’s largest and most successful technology companies, Cubic Corp., died June 23 at the age of 97, the company said June 25.

“He wasn’t in last week, but before that he was working right up until the end, signing documents and making decisions,” said Cubic spokesman Timothy Hill.

Zable was by far, the oldest chief executive of a publicly traded company in the nation, and led an extraordinary life that included founding Cubic in 1951. Cubic evolved into a defense contractor and a maker of mass transit fare collection systems.

He also played football professionally early on and launched an elevator company.

Today, Cubic is a $1 billion company with about 7,800 employees globally, including some 1,200 in San Diego.

“Walter J. Zable has been a wonderful inspiration to Cubic Corp. and its family of companies and its more than 7,800 employees,” said William Boyle, Cubic’s chief financial officer who takes over as interim president and CEO. Zable’s son, Walter C. Zable, was named chairman of the board. Both men are longtime directors and senior executive officers. Zable, 65, is vice president and the vice chairman of Cubic Transportation Systems, a developer and supplier of automated fare collection systems to public transit agencies.

The company’s two other divisions are defense systems, a provider of realistic combat training systems to the U.S. military departments and 35 other allied nations, and mission support services, a provider of training, operations, maintenance and other support services.

Zable rejected the idea of retirement and maintained a regular, five-day-a-week schedule at Cubic. “If I retired I’d be at home, reading technical books and wouldn’t be in the real world,” he said in an interview upon reaching 90.

Owning nearly 40 percent of Cubic stock, Zable was also a perennial member of San Diego’s wealthiest list. Based on the most recent stock price, that stake was valued at about $490 million.