By Katie Paul

Facebook Inc will permanently embrace remote work even after coronavirus lockdowns ease, Chief Executive Mark Zuckerberg said on Thursday, accelerating the tech sector's geographic diversification away from its home in Silicon Valley.

Zuckerberg said the world's largest social network would start "aggressively opening up remote hiring" in July, expecting that about half its workforce would eventually do their jobs outside Facebook's offices over the next five to 10 years.

The company would take a more "measured approach" with existing employees based on job function and past performance, he said, and set a January 1, 2021 deadline for staff to update the company on their new locations for tax purposes.

The move is the most significant yet by a tech giant to reimagine what work culture will look like in a post-coronavirus world, as the pandemic upends office and commuting habits for companies around the world.

It follows similar announcements earlier this month by social media rival Twitter and payments company Square, both led by Jack Dorsey, which were the first tech companies to permit remote work indefinitely.

But Facebook is a much larger company, with nearly 50,000 employees, and it went further in laying out a novel proposed structure for remote work. Its decision is likely to have a pronounced impact on the San Francisco area, where the tech sector's rapid growth has strained regional infrastructure.

Facebook, which has already said it will stick to plans to hire 10,000 engineers and product employees this year, will also build three new "hubs" in Atlanta, Dallas and Denver where remote workers in those areas could occasionally convene.

"These aren't necessarily offices," Zuckerberg said, although the company would likely create "some kind of physical space" to foster community. "The idea for these hubs is that we want to create scale. We want to focus the recruiting energy in some cities where we can get to hundreds of engineers."

The total effect on costs of the shift to remote work is unclear, Zuckerberg said. Savings related to real estate, food and labor costs will be partially offset by additional expenses for travel and logistics associated with home offices.

He said the company was committed to keeping its current office spaces, which include a tony Menlo Park headquarters designed by architect Frank Gehry, featuring a rooftop garden and a courtyard sheltered by redwood trees.

The sky-high compensation packages common in Silicon Valley will not necessarily be transferred to other parts of the country, however. Zuckerberg said salaries will be adjusted if Facebook employees opt to live in less-pricey regions, consistent with the company's existing cost-of-living calculations.

"We pay very well, basically at the top of the market, but we pay a market rate. And that varies by location, so we're going to continue that principle here," he said.

Internal surveys indicate that about 60% of Facebook employees preferred a flexible approach to work, with a mix of remote and office-based functions, Zuckerberg said.

Within that group, he said, just under half reported they would move to another region if given the option.

He said there were no differences in the results by gender.

(Reporting by Katie Paul and Akanksha Rana; Editing by Chris Reese and Dan Grebler)