CNBC suggests passing the 500 investors milestone is likely to trigger the offering.
How much is Facebook worth? According to the latest tech world chatter, more than $100 billion.
That's the figure cited by CNBC in a report claiming that the social network is likely to file for an IPO to take place in the first quarter of 2012, putting a 10-figure valuation on the company.
The story suggests that the trigger for the IPO may be Facebook passing the 500 investor mark - a milestone that would trigger SEC rules requiring it to start publishing quarterly financials.
An IPO would also help current Facebook employees to sell their company shares openly, and cash in on the social network's strong growth - it's thought to be nearing 700 million monthly active users.