Fortune is reporting that Zynga COO John Schappert has resigned. The news comes just a few weeks after Zynga stock tumbled nearly 50% following lackluster quarterly financial results. Schappert himself reportedly lost significant clout following the company's recent reorganization.

"We can confirm that John Schappert has left Zynga and its Board of Directors effective immediately," Zynga CEO Mark Pincus said in an emailed statement. "John has made significant contributions to the games industry throughout his career and we appreciate all that he has done for Zynga. John leaves as a friend of the company and we wish him all the best."Last week's executive shake-up saw both head of mobile David Ko and head of game development Steve Chiang begin reporting directly to Pincus, rather than Schappert. At that time it appeared that Shappert would retain the COO title.Schappert, Pincus and several other Zynga executives have come under fire for dumping millions of dollars in Zynga stock just a few days before the company announced its quarterly results and the stock crashed.Schappert joined Zynga in May 2011, a high-profile defection from Electronic Arts, where he had served as COO since 2009. he previously held executive roles at Microsoft and Tiburon.

Justin is Editor of IGN Wireless. You can follow him on Twitter and IGN