Lew Platt, 64, the former chairman of the board of Boeing Co. who previously led Hewlett-Packard Co. during the boom years of the 1990s, died Sept. 8, reportedly of a brain aneurysm.

Mr. Platt, who took the Silicon Valley computer firm's sales from $16 billion to $47 billion in just seven years, died in Northern California, where he lived.

Mr. Platt was non-executive chairman of the aerospace and defense company's board from December 2003 until June. A member of the company's board since 1999, he found himself in the public eye recently as Boeing struggled to get past defense contracting scandals that sent two executives to jail. This spring, he took temporary charge when chief executive Harry C. Stonecipher -- appointed to help repair Boeing's image -- resigned after admitting to an affair with a female Boeing executive.

It was not his first brush with high-stakes controversy in the business world.

A mechanical engineer who worked at Hewlett-Packard for 33 years, Mr. Platt was considered the quintessential guy next door. In an era of arrogant and egotistical chief executives, he was even-tempered, was known in the company by his first name and waited in the company cafeteria line for lunch.

He was founder David Packard's second choice to run the world's second-largest computer firm in 1992, yet he didn't hesitate to shake it up. Revenue rocketed, as did Wall Street's supercharged expectations.

He told Fortune magazine in 1994: "We have to be willing to cannibalize what we're doing today in order to ensure our leadership in the future. It's counter to human nature, but you have to kill your business while it is still working."

Growth slowed by 1998, and as Wall Street analysts were grumbling about his leadership, Mr. Platt had to forfeit $2.4 million he was to have received in incentive pay after he failed to meet performance benchmarks set by the HP board three years earlier. He then pulled off his most revolutionary move, which stunned old-timers and newcomers in Silicon Valley: He split off HP's original electronic testing and measurement instruments into a separate firm, Agilent Technologies Inc., from the computer products division, which retained the HP name. Then he stepped down.

"Lew doesn't breathe his own exhaust," one Silicon Valley observer told the San Jose Mercury News in 1999. "There isn't an arrogant bone in his body."

He was succeeded by Carly Fiorina, who was ousted this year. Mr. Platt joined Kendall Jackson Wine Estates Ltd. as its chief executive until 2001.

Mr. Platt, who was born in Johnson City, Nev., graduated from Cornell University and received a master's degree in business administration from the Wharton School of Business in 1966. He joined HP's medical products division and worked his way up to chief executive.

Mr. Platt won numerous awards, including Business Week's top manager award in 1995. He was given the Catalyst Award in 1991, which honors corporations that demonstrate a proven ability to advance women in business.

His first wife died in 1981.

Survivors include his wife, Joan Redmund Platt; four children; and a grandchild.