Revealed: The 25 biggest IPOs ever

Facebook is set to raise up to US$16bn in its initial public offering (IPO) on Friday, which could make the social networking phenomenon the seventh largest flotation in global corporate history. The website, founded in a Harvard University dorm by Mark Zuckerberg eight years ago, is expected to float up to 422m shares. However, the cash raised by Facebook is not expected to compete with some of other IPOs seen across global exchanges in recent years. When Visa floated on the New York Stock Exchange in 2008, the payments firm raised US$17.9bn, while automotive giant General Motors raked in US$15.8bn when it went public in 2010. The top three IPOs in history all come from outside of the US though. Japan's NTT Mobile, which floated on the Tokyo Stock Exchange in 1998, raised US$18.1bn from share sales. The top two most expensive public offerings were both seen on Chinese exchanges. Industrial and Commercial Bank of China, which floated on the Hong Kong and Shanghai bourses in 2006, racked up US$19bn. Agricultural Bank of China, which went public two years ago, is the most expensive IPO in history, raising US$19.2bn.