A Mystery Tech Company Is Set To Take Over An Office Project That's Twice The Size Of Facebook's Campus

The city approved a massive office project on Wednesday for an undisclosed tenant, and the rumor mill is churning over who that tenant might be.

The project, worth an estimated $700 million, has space for 8,000 to 10,000 employees, and is spread out over 10 seven-story buildings. At 2 million square feet, it's twice the size of Facebook's Menlo Park, Calif., campus (and bigger than Facebook's new proposed headquarters).

Besides developer Peery-Arrillaga - which has also built campuses for companies such as Apple and Hewlett-Packard - San Jose's mayor, Chuck Reed, knows who the company is. He's keeping mum, but did confirm to the San Jose Mercury News that the company is in the tech sector.

"I can't tell you who Company X is, but there is a company behind the Peery-Arrillaga project," Reed told CBS Local. "It's not a spec building, obviously it's a very big company because they're talking about 2 million square feet of office space, which would be the largest deal we've done in San Jose since the Internet boom went bust and one of the largest in the history of the city."

It doesn't seem likely that the tenant is Facebook or Apple, since the two companies are already planning new campuses of their own up the Peninsula. Perhaps it's Microsoft looking to boost its presence in the Silicon Valley?

We probably won't know until next year. Construction is set to begin sometime in 2014.

We've reached out to developer Peery-Arrillaga and will update this post if they respond.