SAN FRANCISCO (AP) — Dan Porter is leaving Zynga a year after the online game maker bought his company, OMGPop, for $183 million.

Zynga Inc. said Tuesday that Porter has left Zynga's New York office. Sean Kelly has been named as the studio's head.

OMGPop, a mobile game maker, created "Draw Something," a once-popular, Pictionary-like mobile game that has since fizzled. Porter's departure comes as Zynga gets ready to launch the game's successor, "Draw Something 2."

"We thank Dan Porter for his efforts in making the Draw Something franchise a success and wish him well in his future endeavors. We're proud to see talent like Sean Kelly take a bigger leadership role as the Head of our New York studio and lead the team to the global launch of 'Draw Something 2,'" David Ko, Groupon's chief operations officer, said in a statement.

Kelly has been with Zynga since 2009, heading teams that launched games like "CityVille" and "Running With Friends."

San Francisco-based Zynga's fortunes have declined with the popularity of its games, which include FarmVille. Revenue has flattened along with its stock price.

Zynga shares fell 9 cents, or 2.9 percent, to close at $3.07. The stock has traded in a 52-week range of $2.09 to $12.90.