San Jose, Calif. ? Al Sisto wouldn’t knowingly expose his employees to SARS, nor would he jeopardize his software firm’s revenue, two-thirds of which comes from Asia.

So while the president and CEO of Phoenix Technologies declared all travel to Asia voluntary, he also upgraded his company’s Web-based video conferencing equipment.

Sales representatives who last month considered a flight from San Francisco to Hong Kong part of their commute now woo clients in cyberspace from offices in San Jose.

“For the keynote speeches, the high-level meetings, the gatherings of senior executives to further our relationships — that’s where we’ve had to do a bit of a switcheroo and move to the Web and video conferencing,” Sisto said.

Phoenix joins a growing list of Silicon Valley companies using technology as an antidote to traveling to SARS-inflicted places, many of which happen to be critical manufacturing centers of microchips and buyers of local firms’ finished products.

The World Health Organization said Wednesday that people should postpone unnecessary travel to Toronto, Hong Kong, Beijing and other parts of China because of sudden acute respiratory syndrome, which has killed about 260 people and infected more than 4,300 worldwide.

Although few companies are reporting manufacturing slowdowns or stalled product launches, American executives fear SARS could lead to the shuttering of factories or office parks, bungle business relationships or stifle consumer demand in one of the tech industry’s most important regions.

But they’re hoping the newest generation of high-speed, zero-delay conferencing hardware and software — as well as e-mail and instant messages — will provide an emergency measure of interpersonal relationship building, a crucial tenet of Asian business.

Communication between Silicon Valley and Asia is essential. The continent produces billions of computer parts each year, and low-cost contract workers maintain computer systems and develop software for hundreds of Silicon Valley companies.

Al Sisto, left, CEO and president of Phoenix Technologies, speaks with George Man, vice president and general manager of the company's Asia Pacific division, in a demonstration of their video conference system at the company's San Jose, Calif., headquarters. The use of video conferencing has increased because of the SARS epidemic, which has closed schools and stalled travel to and within Asia. Some business experts say the technology could prove more than a temporary antidote to the mysterious illness, permanently transforming Asia's business culture.

Asia and Australia accounted for 38 percent of revenues at Santa Clara-based Intel Corp. in the last quarter of 2002, and it was the chip maker’s leading revenue generator for the previous three quarters.

Microsoft Corp., which has more than 4,000 employees in Asia, extracts about 20 percent of its global revenue from the region. Asia has been the Redmond, Wash.-based software giant’s fastest growing market for at least three years.

Instead of flying to Tokyo, Guerrino De Luca, CEO of Logitech International, conducted a live interview last week with Japanese journalists via a new Polycom video system with TV-sized screens installed in the consumer electronics company’s Fremont headquarters.

Although the company lifted its two-week ban on travel to and within Asia on Monday, Logitech is asking employees to become familiar with telecommuting procedures as well as teleconferencing.

About 3,000 of Logtitech’s 4,000 workers are in Asia, mainly at manufacturing plants in China.

Santa Clara-based Sun Microsystems Inc. has long encouraged employees to telecommute. Sun broadened its iWork program last month in case offices in Asia are shut down or workers quarantined.

Redwood City-based Oracle Corp. is asking employees to avoid nonessential travel to Asia. Upon return from a SARS-infected country, employees are asked to telecommute for five days.