Box CEO Aaron Levie

Box, the file sharing and data storage startup founded seven years ago by Mercer Island High School grads Aaron Levie and Dylan Smith, has reeled in a whopping $125 million venture round led by General Atlantic.

The financing follows an $81 million deal that the Los Altos, California company raised last fall, building a substantial arsenal for the company as it competes with the likes of Dropbox, Microsoft and Amazon’s Simple Storage Service. Total funding at Box, which has doubled staff to more than 500 people in the past year, stands at $287 million.

Last week, The Wall Street Journal reported that the new round of cash was being raised at a $1.2 billion valuation, coming on the heels of the company turning down a $700 million buyout offer from Citrix.

“The confluence of cloud, mobile and social technology is transforming how every enterprise and individual manages information today,” said Levie in a statement. “This new funding allows us to invest aggressively in the talent, technology and global expansion efforts required for Box to sit at the center of this shift and define the next generation of enterprise software.” The company did not disclose its growth plans for the coming year.

Despite growing up in Microsoft’s backyard, Levie and crew are anything but supporters of the software giant. In fact, Levie has routinely criticized Microsoft, suggesting that the company has lost its innovative edge. That’s creating an opening for companies like Box, he says.

When Box raised cash last fall, Levie noted:

“Businesses of all sizes are moving their information and collaboration to the cloud, and with this new capital we’ll support their transition by continuing to aggressively out-innovate legacy players like Microsoft.”

Today’s press release doesn’t include any Microsoft references. But Levie has continued to reference Microsoft in his popular Twitter stream, just yesterday writing:

Microsoft’s challenges are simple. They put a computer on every desk and in every home but forgot to put one in everyone’s hand.

Box founders Dylan Smith and Aaron Levie

Box has continued to add enterprise customers at the expense of Microsoft, but also winning customers from another Seattle tech titan: Amazon.com. Though it didn’t disclose revenue figures, Box’s enterprise sales are growing by more than 200 percent year-over-year.

In addition to General Atlantic, other participants in the round include Bessemer Venture Partners, DFJ Growth, New Enterprise Associates, SAP Ventures and Scale Venture Partners. New investor Social+Capital Partnership also participated. As a result of the financing, General Atlantic’s Gary Reiner has joined the board.

Given Box’s connections to the Seattle area, I’ve often referred to the company as the “one that got away.” Levie and Smith moved the company to Silicon Valley in 2006 shortly after it was founded, choosing the Bay Area because it had entrepreneurial buzz for young tech founders.

Editor’s note: Box CEO Aaron Levie will be one of the keynote speakers at GeekWire’s Startup Day on September 22. Details and tickets here.

Like what you're reading? Subscribe to GeekWire's free newsletters to catch every headline

Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.