Facebook Files For $5 Billiion IPO; Co-Founder Zuckerberg Holds 28.4% Of The Stock, Accel, 11.4%: UPDATED

Facebook filed for a $5 billion IPO on Wednesday as the social networking site with $3.7 billion in 2011 revenue opened up the details of its business to public scrutiny for the first time.

The company’s top shareholder is CEO Mark Zuckerberg, who co-founded the company in a Harvard dorm room and holds 28.4% of its class B stock, according to an S-1 filed with the Securities and Exchange Commission. Second on the list is Accel Partners, an early investor.

The filing shows that Facebook now has 845 million monthly users, up 39% from last year, and a powerful business. Only 161 million of users come from the United States, which shows its international diversity. About half of users access the site with a mobile device, which shows its broad appeal.

The company plans to employ two classes of stock after its offering. Its class A shares, with a single vote per share, will be sold to the public. Class B shares come with 10 votes and are held by insiders, such as Zuckerberg, who has 534 million of them.

Accel Partners, also a class B holder, has 11.4% of the stock, or 201 million shares, while Russian investor Yuri Milner’s DST Global Limited has a 5.4% class B ownership stake, as well as 36 million class A shares. According to the S-1, DST Global is locked up from selling its shares for 12 to 18 months after the IPO.

Dustin Moskovitz, a co-founder and Zuckerberg classmate, has 7.6% of the outstanding class B shares. Other top owners include board member Peter Thiel, who holds 45 million class B shares, or 2.5% of the company, and board member Marc Andreessen, whose firm Andreessen Horowitz has 3.5 million. T Rowe Price Associates holds a mix of 18 million class A and B shares, and Goldman Sachs speaks for 66 million class A shares.

It is clear from the filing that Facebook has a substantial business likely to generate considerable excitement on Wall Street. Net income last year was $1 billion and cash on hand is $3.9 billion.

Revenue from advertisers and platform developers in the United States accounted for 56% of sales at the company last year in part due to a 42% increase in the number of ads delivered and an 18% hike in the average price per ad. Zynga accounted for 12% of revenue through fees from the sales of virtual goods and from direct advertising it purchases.

Of Facebook users, 46 million come from India and another 37 million in Brazil. Interestingly, Facebook lists Google’s Orkut, which is strong in Brazil, as well as Google+ as significant competitors.

Another challenge is China. China has restricted the use of Facebook.

(Update: additional detail from the S-1 is added throughout.)