Check-in cha-ching: Foursquare raises $50M with a $600M valuation

Location-based social network Foursquare closed a new $50 million round of funding, the company reported today.

Foursquare said it will use the new funding to hire additional engineers, grow its merchant platform and expand internationally.

“The opportunity to build something meaningful in the location space is HUGE, and we feel well-positioned to capitalize on it,” co-founders Dennis Crowley and Naveen Selvadurai wrote on the company’s blog.

TechCrunch is reporting Foursquare’s valuation at $600 million — with additional rumors putting the valuation as high as $1 billion.

The new round, which was led by Andreessen-Horowitz, includes funding from O’Reilly AlphaTech Ventures, Union Square Ventures and Spark Capital. Foursquare raised a $20 million round last year and received angel funding in the fall of 2009. The company has raised a total of $71.4 million to date.

The New York-based startup has added more than 70 employees to the company and more than 10 million new users to its service in the last two years.