Zynga Inc shareholders will sell Class A shares worth about $591 million, with founder and CEO Mark Pincus alone set to reap about $227 million based on Thursday's closing price.
Shareholders will sell a total of 43 million shares in the online game maker, including 16.5 million from Pincus, the company said in a regulatory filing on Friday.
Private equity firm Union Square Ventures is among the selling stockholders.
Zynga waived a lock-up arrangement to facilitate the offering. Investors are typically expected to wait about six months after an initial public offering to sell their shares.
Pincus will have 35.9 percent of the voting shares after the sale, down from 36.5 percent now.
Zynga has three classes of stock. Class A shares carry one vote each, Class B seven votes and Class C 70 votes.
Zynga which is trying to minimize its dependence on Facebook, announced its biggest-ever acquisition on Wednesday, buying OMGPOP, maker of the popular game Draw Something.
The company said it paid $180 million for OMGPOP.
Morgan Stanley and Goldman Sachs are the lead underwriters for the offering.
Zynga shares, which have risen 33 percent since the company went public in December, closed at $13.76 on Thursday.
(Corrects paragraph 3 to remove reference to Kleiner Perkins Caufield & Byers, which is not selling shares)
(Reporting by Himank Sharma in Bangalore; Editing by Sreejiraj Eluvangal)