Activision Blizzard has restructured its executive team. The company didn’t announce the changes, but a memo obtained by the Los Angeles Times described the changes. Activision Blizzard has confirmed what the newspaper reported.

The Santa Monica, Calif.-based company, the largest independent video game publisher, divided itself into four units in the biggest reorganization since the merger of Activision and Blizzard in 2008.

Call of Duty will be a business division unto itself. But it’s a little unclear what kind of shape that division is in, given the firing of two co-founders at game studio Infinity Ward, which made the Call of Duty games. Blizzard Entertainment, maker of games such as Starcraft II and World of Warcraft — the cash cow of the whole company — will remain on its own as a separate division.

A third division will handle internally-owned game properties (headed by Maria Stipp), such as the Tony Hawk and Guitar Hero franchises. Guitar Hero was once a division by itself, but sales of that music game series have plummeted. A fourth division will handle licensed properties such as Marvel character game Spider-Man.

Mike Grifffith, who previously oversaw all of Activision’s publishing excluding Blizzard, is now vice chairman. He serves as an advisor to chief executive Bobby Kotick (pictured). Thomas Tippl, formerly chief financial officer and chief corporate officer, is now chief operating officer, reporting to Kotick. Tippl oversees Blizzard President Mike Morhaime. Tippl is temporarily filling out the role of head of Activision Publishing.

The latter move seems a little suspicious to me. Morhaime is running the best-performing division in the company. Why put someone over him? The Los Angeles Times said the memo describing the changes was sent to employees last week.

“This is an important change as it will allow me, with Thomas, to become more deeply involved in areas of the business where I believe we can capture great potential and opportunity,” Kotick said in the memo to employees.

[photo: Elisabeth Caren]