Investment fund GSV Capital Corp has taken a small stake in Facebook that values the world's No. 1 social networking site at about $70 billion.

The investment fund said on Monday that it had bought 225,000 shares in Facebook at an average price of $29.28 each.

Facebook has roughly 2.4 billion outstanding shares, according to the latest data from secondary market company Sharepost.

Facebook executives have said it is inevitable that they will take the company public, but have not specified a date.

Founded in a Harvard dorm room in 2004 by Mark Zuckerberg, Facebook threatens Internet stalwarts like Google Inc and Yahoo Inc as it becomes one of the most popular destinations on the Web.

It is poised to overtake Yahoo for the biggest slice of U.S. online display advertising dollars this year, with more than $2 billion, according to research firm eMarketer.

Facebook is one of the most anticipated initial public offerings, with investors to clamoring to get a piece of the social networking site with more than 500 million users.

At $70 billion, Facebook would be valued slightly below Amazon.com Inc, Cisco Systems Inc or Hewlett-Packard Co.

But concerns about Facebook's white-hot growth have surfaced in recent months. A group of Facebook shareholders is trying to sell $1 billion of stock on the secondary market in a transaction that also would give the company a value of about $70 billion, Reuters reported in April.

Woodside, California-based GSV Capital invests in high-growth, venture capital-backed companies. The $6.6 million investment in Facebook represents about 15 percent of GSV's total portfolio, the company said in a statement.

Representatives of Facebook and GSV Capital were not immediately available for comment.

Shares of GSV Capital were up 20.3 percent at $12.35 in morning trading.

(Reporting by Jennifer Saba, editing by Gerald E. McCormick and Lisa Von Ahn)

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