The Los Angeles Times is reporting that Activision has signed on a third game development studio to work on future Call of Duty titles.

The report also states that a source close to company says it was considering adapting a "massively multi-player online world" for Call of Duty, which CEO Bobby Kotick hinted at last year about possibility of developing a MMO title for the series.

No other details about the unnamed studio or its project were given.

Right now, Activision has developers Infinity Ward and Treyarch alternating its major Call of Duty releases. If a third studio is developing a full console game, a few choices could be Raven Software from the recent release of Wolfenstein, or Sledgehammer Games, which is headed up by famed Dead Space producer Glen Schofield.

Of course, this studio could be focuses on mobile games for the iPhone or Nintendo DS, which wouldn't be nearly as exciting.

We'll keep you posted as long as Activision keeps milking sequels.