Call of Duty publisher Activision Blizzard is looking to further expand the blockbuster series by adding a third development studio to the mix, claims a Los Angeles Times report.

Recent years have seen the company release annual entries by alternating lead development duties between series creator Infinity Ward (Call of Duty, Call of Duty 2, Call of Duty 4: Modern Warfare, Call of Duty: Modern Warfare 2) and Treyarch (Call of Duty 3, Call of Duty: World at War), with external studios n-Space and Rebellion having assisted with Nintendo DS and PlayStation 2 editions.

Activision claims that this year's entry, Modern Warfare 2, represents "the biggest launch in history across all forms of entertainment," with indications that the inevitable next one will be handled by Treyarch and could be set in Vietnam.

The publisher has also repeatedly spoken of a possible Call of Duty-branded massively multiplayer game, with CEO Bobby Kotick pondering how to monetize "the natural evolution of a property like Call of Duty into a massively multiplayer environment" and CFO Thomas Tippl noting "you should expect us to test and ultimately launch additional online monetization models of some our biggest franchises like Call of Duty."

Source.