Zynga to soon file $15-20 billion IPO - Report

Rumors of an initial public offering by Zynga have been bouncing around for several weeks. However, now CNBC is reporting that the publisher of FarmVille will shortly file paperwork with the Securities and Exchange Commission for an IPO. Citing "people familiar with the matter," the financial site says that the San Francisco-based company may submit the forms as soon as Wednesday of this week in anticipation of a fall public offering.

Zynga is the creator of the wildly popular casual games FarmVille, CityVille, and Mafia Wars, which are played on the Facebook social network. CNBC expects the game company's public offering to be huge, in the range of $15 to 20 billion. Previously, the privately held company was valued at $10 billion--more than megapublisher Electronic Arts' market capitalization.

Zynga's IPO will come more than a month after the company hired away EA's COO John Schappert. The company is also negotiating with the city of San Francisco for an exemption to a payroll tax that affects payments gleaned from IPOs.