Facebook games developer Zynga Inc will sell about 15 percent of its common stock in an initial public offering, Bloomberg said, citing a person with knowledge of the matter.

Zynga plans to sell shares for $8.50 to $10 apiece in its initial public offering to raise as much as $1 billion, valuing the company at as high as $7 billion, the agency said.

Dani Dudeck, a spokeswoman for Zynga, declined to comment to Reuters on the Bloomberg report.

Zynga rose to prominence on viral games such as Farmville, which is still among one of the most popular games on the Facebook social network. While its games are free, Zynga makes money from selling virtual items such as tractors and weapons that people use in its game worlds.

(Reporting by Sakthi Prasad in Bangalore; Editing by Phil Berlowitz)