The Palo Alto, Calif.-based social network plans to offer over 337 million Class A shares at between $28 and $35 per share. It’s an unusually wide range for such a filing, with most prospective issuers usually only using a $3 spread (e.g., $28-$30).

Facebook will formally launch its roadshow next week, with Morgan Stanley, J.P. Morgan and Goldman Sachs serving as co-lead underwriters. The company’s “e-roadshow” is available here.

It plans to trade on the NASDAQ under ticker symbol FB, with the actual pricing expected to come later this month.

The company also today said that 180 million of the offered shares would come from the company itself, while the remainder will come from insiders. Here’s a list of who plans to unload part of their stakes:

• Accel Partners: 35.9 million shares, which would leave it with around 153 million shares
• DST Group: 26.25 million shares being offered, left with around 105 million shares
• Goldman Sachs: 13.19 million  sharesbeing offered, left with around 53 million shares
• Elevation Partners: 4.6 million shares being offered, left with around 36 million shares
• Meritech Capital Partners: 7 million shares being offered, left with around 33 million shares
• Mirosoft: Offering 6.56 million shares, left with around 26.23 million shares
• Reid Hoffman: 942k shares, left with just over 3.77 million shares
• Mark Pincus: Around 1 million shares, left with just over 4.3 million shares
• Greylock Partners: 7 million shares, left with around 30 million
• Tiger Global Management: 6.56 million shares, left with around 50 million shares
• Jim Breyer (individual, not via Accel): 2.31 million shares, left with around 9 million shares

T. Rowe Price and Andreessen Horowitz are the only significant institutional holders not planning to offer any shares, holding onto all 18 million. Other notable “holders” include Sean Parker (66 million) and Dustin Moskovitz (134 million) — although both would sell millions of shares as part of the underwriter’s “green shoe” option, if exercised. It also appears that Parker sold more than 3 million shares via private placement within the past 5 weeks — termed a “transfer” — but details are not specified.

Facebook CEO Mark Zuckerberg plans to sell around 30.2 million shares, which he says will be used to settle tax obligations.

It’s also worth noting that the IPO range has an impact on how much Facebook really paid for mobile photo-sharing company Instagram, which it agreed to acquire last month. When announced, the deal was said to be for $1 billion. That includes $300 million or cash, and 23 million shares of Facebook stock. If Facebook prices at the low end of its range, that brings the acquisition price to $944 million. At the high end, $1.1 billion.

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