SAN FRANCISCO – Yahoo Inc. is a pioneering company in Silicon Valley, a region famous for its laid-back, employee-friendly corporate cultures.

That’s why Yahoo’s move to discourage workers from working from home, while sparking some mixed reactions, is viewed by many as a risky gamble at odds with the Silicon Valley tradition.

In a memo to employees, first reported by AllThingsD, Yahoo’s human resources chief said that beginning in June, “We’re asking all employees with work-from-home arrangements to work in Yahoo offices.”

“Being a Yahoo isn’t just about your day-to-day job; it is about the interactions and experiences that are only possible in our offices,” the memo said.

The news was particularly striking since Yahoo Chief Executive Marissa Mayer, in her bid to turn around the struggling Web portal, has made the company’s employees one of her priorities.

“Talent is fundamental to our success,” she said on the company’s last earnings call. “Attracting the best people to Yahoo is critical, and we’ve embarked on a number of initiatives to make Yahoo the absolute best place to work.”

But Yahoo’s work-in-office push runs counter to corporate culture in Silicon Valley, where the region’s tech industry has long been known for flexible working hours and other conditions.

Hewlett-Packard Co., which was founded in 1939, perhaps the most iconic of the valley’s companies, helped popularize the practice of using cubicles, even for top executives.

Newer companies, such as Google and Yahoo, were famous for giving employees plenty of perks, including free food.

Yahoo’s own co-founder Jerry Yang used to write notes to employees, whom he called “yahoos,” using only lowercase letters.

Companies reached by MarketWatch, including HP, LinkedIn Corp. and Facebook Inc. said they don’t have any set policies on working from home, leaving it to managers to make a decision.

“When you’re talking about different time zones, you have other considerations,” a Facebook spokesman told MarketWatch. “So it’s very flexible in that respect. It’s something that is an option for people to consider depending on what they’ve got going on.”

Yahoo declined to comment for this report.