Vice president of studios Bill Mooney and vice president of marketing Brian Britwistle today announced that they will be leaving their positions at social gaming giant Zynga.

The announcement follows Tuesday’s news that chief creative officer Mike Verdu is leaving Zynga as well to form his own company in which Zynga CEO and Founder Mark Pincus will be an investor.

Earlier this month John Schappert also left his role as Zynga’s COO and his position on the company’s board of directors.

Zynga spokes person Dani Dudeck responded with the following statment: “Zynga’s voluntary attrition rate was around 1% for the first four years, and our current attrition levels are not only below what we expected and modeled in our post-IPO planning, they continue to stay well below the industry average.  Developing great leaders is an essential part of Zynga’s core values – we’re proud of our record in that regard – and it’s not at all surprising that some would move on and or retire post-IPO.  Zynga continues to lead the industry with the top talent in social game development. We’re proud of the teams working hard to create the next generation of social games including the recent launches of The Ville, ChefVille and the coming launch of FarmVille 2.”