Netscape founder Marc Andreessen said in an interview that he expects Facebook's revenue to be in excess of $500 million in 2009, and estimates that in five years,  it'll be well into the billions.

The Internet pioneer also announced on Monday that he is launching a venture capital firm, Andreessen Horowitz, with his longtime business partner Ben Horowitz. The firm will invest in digital companies of any size and of any kind and at any stage in their lifecycle.

He adds that the firm is also willing to take equity stakes in public companies. We are unafraid of investing in 400 people instead of 40 people, Andreessen says. And we could invest $50,000 to $50,000,000.

Meanwhile in an interview with Reuters,  Andreessen said that Facebook is on track to make billions of dollars in annual revenue in five years, among the first projections about the social networking giant's long-term prospects from an insider. He joined Facebook's board a year ago.

Generally speaking, people who are selling their stock in Facebook now are making a mistake, he told Reuters regarding the fact that since an initial public offering is still a ways off, Facebook is permitting some employee stock sales to Digital Sky Technologies, the Russian firm that invested $200 million in the site in May.

Andreessen himself is not a personal investor in Facebook, and said that I probably could have if I had tried hard but I didn't.

Andreessen and Horowitz worked together at Netscape Communications Corp. and Opsware Inc., two companies that were sold for a combined $11.7 billion.