The social networking site has raised funds from Goldman Sachs and a Russian investor.
According to the New York Times, the deal values Facebook at $50bn, with Goldman investing $450m and Digital Sky Technologies another $50m.
The Financial Times also reported that Goldman was investing $375m in Facebook, with Digital Sky putting in $75m.
Speculation that Facebook might float on the stock market could come from Goldman’s involvement.
Goldman refused to comment, as well as a spokeswoman from the social networking site.
If the newspaper’s story is true, valued at $50bn Facebook is worth more than eBay and Time Warner.
The New York Times said the fresh investment will probably be used to fund development of new products and possibly make acquisitions. It may also enable Facebook employees and early investors to cash in some of their stakes.
The Securities and Exchange Commission (SEC) is looking at the growth in the private market for trading in companies such as Facebook, Twitter, and LinkedIn, the newspaper wrote.
Regulators worry that this private market booming might enable companies to circumvent public disclosure requirements.
And even though Facebook’s founder, Mark Zuckerberg, has denied any plans for a flotation, further scrutiny by the SEC could help push the social networking site towards a public listing.