Activision Blizzard Inc has countersued two former executives, charging them with attempting to hijack the company's assets and threatening the future of its blockbuster Call of Duty video game franchise.

Activision fired Jason West and Vincent Zampella, who lead the Infinity Ward studio, last month. The men subsequently filed a lawsuit against Activision, seeking $36 million in royalty payments and damages.

Infinity Ward, which was acquired by Activision in 2003, developed the original Call of Duty game and several others in the series.

In a cross-complaint filed on Thursday in California Superior Court in Los Angeles, Activision said it fired both men for cause after they violated their employment contracts and their fiduciary duties to the company.

The complaint charged that West and Zampella were insubordinate and self-serving schemers who negotiated with competitors while under contract, and tried to prevent Activision from compensating Infinity Ward employees in order to make them easier to poach when the men departed to set up their own company.

It also charged that West and Zampella held future Call of Duty versions hostage because of their demands.

Robert Schwartz of O'Melveny & Myers, who is a lawyer for West and Zampella, did not have any immediate comment but said he may comment later.

Call of Duty: Modern Warfare 2, the sixth installment in the series, was released late last year and sold nearly 12 million units in the United States, Japan and the United Kingdom in 2009. It set a record for first-day sales, moving 4.7 million copies and pulling in an estimated $310 million.

After firing West and Zampella, Activision formed a business unit for the Call of Duty franchise. A new title is scheduled for release this fall.

The case is Jason West v Activision Publishing, Superior Court of the State of California, No. 107041

(Reporting by Gabriel Madway; Editing by Phil Berlowitz)