Washington, Feb 08  : Facebook CEO Mark Zuckerberg's stake in his company has been reportedly reduced to just under 20 percent, a company filing has revealed.

Zuckerberg now owns 478.9 million shares of Facebook, or 19.6 percent of all shares, compared to last year's 30 percent share.

According to Mashable, Zuckerberg had sold a chunk of his shares in December last year, amounting to 2.3 billion dollars, largely to pay his tax bills for options that he exercised.

He had pledged in September 2012 not to sell any shares of Facebook for at least a year, to show his confidence in the stock at a time when it had hit a new low.

The report said that Facebook's stock doubled throughout 2013, driven by renewed optimism for the social network's ability to make the shift to mobile and Zuckerberg's net worth increased by 12.4 billion dollars for the year. (ANI)