Investment banking giant Goldman Sachs has invested $450 million (£290 million) in the latest round of private share sales for Facebook, bringing the value of the company to around $50 billion (£32 billion).
Russian investor Digital Sky Technologies also bought into the social network site, taking up £32 million worth of shares.
A New York Times report suggests that, as a result, Facebook is now worth more than eBay, Yahoo and Time Warner.
"The new money will give Facebook more firepower to steal away valuable employees, develop new products and possibly pursue acquisitions - all without being a publicly traded company," read the report.
"The investment may also allow earlier shareholders, including Facebook employees, to cash out at least some of their stakes."
Even though Facebook CEO Mark Zuckerberg has warned people not to hold their breath when it comes to Facebook being publicly listed, there are suggestions that the shares could be widely available in 2012.
"When you think back to the early days of Google, they were kind of ignored by Wall Street investors, until it was time to go public," said Chris Sacca, former Google employee and Twitter investor.
"This time, the Street is smartening up. They realise there are true growth businesses out here. Facebook has become a real business, and investors are coming out here and saying, ‘We want a piece of it.’"