Highwinds Network Group on Tuesday said it closed a $55 million round of venture financing led by General Catalyst Partners and Alta Communications.

The funding will be used to expand Highwinds’ Rolling Thunder network, the company’s private network that shuttles web content, file downloads, and streaming media for its customers in North America and Europe.

“Our network is large and high performing and very capable of delivering content, and we felt there was a huge opportunity for companies to expand into [the content delivery] market,” said Mark Hayes, VP of marketing and business development for Highwinds.

The Winter Park, Florida-based company aims to move forcefully into the growing content delivery services market. These networks have become increasingly popular with companies that have rich media, such as video or games, to deliver to their customers over the Internet.

But Highwinds will be entering an industry that already has established leaders in Tempe, Arizona-based Limelight Networks; Akamai of Cambridge, Massachusetts; and San Jose, California’s CDNetworks.

Highwinds also announced that it will collaborate with Digital Rapids and Knack Networks to develop and market “end-to-end” video distribution solutions.

This was Highwinds’ first equity financing round. It previously had debt rounds for undisclosed amounts of money.