Google, operator of the world's biggest search engine, raised $1.9 billion in its 2004 IPO, including an over- allotment option. Zynga is selling all of the 100 million shares in the offering and expects net proceeds of about $889 million, according to the filing. That would add to a cash pile that totaled $604.2 million as of Sept. 30. If underwriters exercise an option to buy 15 million additional shares in the over-allotment, then venture backer Avalon Ventures would sell the largest portion at more than 2.5 million. Founder and Chief Executive Officer Mark Pincus, who isn't selling any shares in the offering, will have about 37 percent voting control once the offering is complete. If the over-allotment is exercised, Foundry Group and Institutional Venture Partners would each sell about 2.5 million shares, while Union Square Ventures would offer 2.2 million. Venture firm Kleiner Perkins Caufield & Byers, Zynga's biggest shareholder after Pincus, isn't selling shares in IPO.