The filing showed Thiel, a board member at Facebook, now owns just 63,550 Class A shares independently and through another fund after selling a stake worth $4 million last week, including the shares he indirectly held through Founders Fund.

That leaves the former PayPal CEO with just over 0.1% of the 44.7 million shares he held in the company when it went public in 2012.

Representatives of Founders Fund and Thiel did not immediately respond to requests for comment.

Launched with $50 million in 2005 by Thiel, Ken Howery, Luke Nosek — all co-founders of PayPal — and Napster co-founder Sean Parker, Founders Fund has invested in companies including SpaceX and Airbnb in their early stages.

Thiel sold 16.8 million of his own shares at Facebook's 2012 initial public offering for about $640 million. Later the same year, he sold roughly another 20 million for $400 million after the expiry of a lockup.

The billionaire is also known for funding the Hulk Hogan lawsuit that led to the shutdown of online news site Gawker. He became a Facebook investor in 2004 with an initial investment of $500,000 at a $5 million valuation.

The only major Silicon Valley name to back President Donald Trump, some have called for Thiel's removal from Facebook's board. Chief Executive Officer and co-founder Mark Zuckerberg has said he should stay, citing the importance of diversity of opinion at the company.

(Reporting by Munsif Vengattil and Sittrarasu S in Bengaluru; Editing by Patrick Graham)