Former Intel CEO Paul Otellini, who led the company from 2005 to 2013, died on Monday at the age of 66, the technology firm announced Tuesday.

Intel said Otellini passed away in his sleep.

“We are deeply saddened by Paul’s passing,” current Intel CEO Brian Krzanich said in a statement. “He was the relentless voice of the customer in a sea of engineers, and he taught us that we only win when we put the customer first.”

Others in the tech industry, including Apple CEO Tim Cook, Senior Vice President of Worldwide Marketing Philip Schiller and Google CEO Sundar Pichai, went on Twitter to offer their condolences.

“Our condolences to the Otellini family and everyone at Intel. Paul was a great friend of Apple,” said Cook on Twitter.”

“Saddened by the passing of Paul Otellini,” said Pichai in a tweet. “He was an amazing leader and technologist, and we were so fortunate to have his leadership and guidance on our board. It's hard to imagine not having him to turn to - we'll miss you, Paul.”

“Very sad about the passing of our board member, Paul Otellini,” said Alphabet Executive Chairman Eric Schmidt on Twitter. “He transformed Intel's business, was an incredibly wise leader, great friend.

Paul Otellini’s Career At Intel

Otellini was Intel’s fifth CEO -- and the first who did not have an engineering background. He had a bachelor’s degree in economics from the University of San Francisco in 1972 and an MBA from the Haas School of Business at the University of California, Berkeley in 1974. He joined Intel in 1974 and worked his way up through various positions at the company.

“Paul’s business acumen, optimism and dedication fueled our growth throughout his tenure as CEO,” Intel Chairman Andy Bryant said in a statement. “His tireless drive, discipline and humility were cornerstones of his leadership and live on in our company values to this day.”

Otellini led the company during the recession, and under his command Intel generated more revenue during his eight-year time as CEO than it did during the previous 45 years. A year before Otellini was named CEO, Intel had $34 billion in sales. By 2012, a year before his retirement, the number had grown to $53 billion. Under Otellini’s tenure, Intel went on to partner with other companies, including Apple’s PC business.

Paul Otellini Net Worth

Otellini was paid $19 million in 2012 before he left Intel. That year, he received a 10 percent raise, with his salary increasing from $1.1 million to $1.2 million, while his incentive cash bonus spiked from about $4.8 million to $5.3 million.

Otellini Retirement

After he retired, Otellini spent his free time mentoring young people and was involved in philanthropic and charitable organizations, Intel said.

Otellini, born in San Francisco on October 12, 1950, would have turned 67 next week. He is survived by his wife, whom he was married with for 30 year, and his son and daughter.