Facebook unveiled plans for the biggest-ever internet initial public offering - it could raise as much as $10-billion - but made it clear that CEO Mark Zuckerberg would exercise almost complete control over the company, leaving investors with little say.

The Harvard dropout, who launched the social network from his dorm room, will control 56.9% of the voting shares in a company expected to be valued at up to $100-billion when it goes public.

Facebook says it has 845million active monthly users.

Wednesday's long-awaited filing kicks off a process that will culminate in Silicon Valley's biggest coming-out party since the heyday of the dotcom boom - which ended with an earth-shattering bust.

In its filing, Facebook says it wants to raise $5-billion but analysts estimate it could tap investors for $10-billion.

That would value the company at $100-billion, dwarfing storied tech giants such as Hewlett-Packard.

Zuckerberg's control of about 28% of the shares would be worth $28-billion at a $100-billion valuation, ranking him as the fourth-richest American.

The 27-year-old's ownership position means Facebook will not need to appoint a majority of independent directors or set up board committees to oversee compensation and other matters.

The company's ownership structure and bylaws go against corporate governance practices put in place in the US after years of investor activism.

Facebook states Zuckerberg will "control all matters submitted to stockholders for vote, as well as the overall management and direction of our company".

Zuckerberg struck deals with several Facebook investors that granted him voting rights over their shares in all or most situations.

Google's Sergey Brin and Larry Page retained control of the search giant with similar arrangements and the Sulzbergers did much the same at the New York Times.

"Zuckerberg, at the time, probably had his choice of investors," said Steven Kaplan, a professor at the University of Chicago's Booth School of Business, who researches venture capital and corporate governance.

"He basically had the ability to say: 'My way or the highway'.

"The downside of doing this is that the value of Facebook might be slightly lower than it would be if he were not retaining control."

Facebook could make its market debut in the middle of the year, based on the usual timetable for IPOs.

Its IPO prospectus shows that Facebook generated $3.71-billion in revenue and made $1-billion in net profit last year, up 65% from the $606-million it made in 2010.