Startup website Foursquare, a location-based services company, said it has raised $20 million in new funding.

The funding was led by Silicon Valley venture-capital firm Andreessen Horowitz and Foursquare's original investors, Union Square Ventures and O'Reilly AlphaTech Ventures.

Foursquare said on Tuesday that it would use the funding to expand the company. Foursquare cofounder Dennis Crowley said in a company blog post on Tuesday that the funding would also allow it to move into a new office and invest in other infrastructure.

The company has about 1.8 million users, Crowley said.

(Reporting by Maria Aspan)