In a complaint filed with California Superior Court for Los Angeles County on Tuesday, Activision sought to add Electronic Arts as a defendant in a case against two former executives who developed the "Call of Duty" video game franchise.
In April, Activision countersued former executives Jason West and Vincent Zampella, charging them with attempting to hijack the company's assets and threatening the future of "Call of Duty" franchise.
Activision's counter charge was in response to the duo's lawsuit against the company, which challenged their dismissal and sought $36 million in royalty payments and damages.
Activision said on Tuesday that West and Zampella broke their long-term exclusive employment agreements to set up their own independent company to develop games for Electronic Arts instead of Activision.
Electronic Arts had signed a publishing and distribution deal with Respawn Entertainment, a new company formed by West and Zampella after their ouster from Activision.
"As a result, Activision has suffered damages measured not in the millions, but hundreds of millions of dollars," Activision said in the filing.
Electronic Arts could not immediately be reached for comment by Reuters outside regular U.S. business hours.
Activision Blizzard is the world's largest stand-alone game publisher and is home to popular games like "Call of Duty" and "World of Warcraft: Cataclysm."
Electronic Arts, which made its name on sports games, publishes famous titles like "FIFA 11" and "Need for Speed."
The case is Jason West v Activision Publishing, Superior Court of the State of California, No. 107041