Activision, the second largest US video games publisher, has become the latest company to be investigated by the Securities and Exchange Commission over its practices in awarding stock options.
The company said on Friday it had received a letter of informal inquiry from the SEC requesting certain documents and information and would cooperate fully.
Activision said it had appointed an independent committee to carry out an internal review of its practices.
The SEC is investigating more than 80 companies over possible manipulation of the award dates for options and federal prosecutors have been focusing on technology companies in California.
Take-Two in New York and now Los Angeles-based Activision are the two video games publishers to be investigated.
Shares in McAfee, the security software company, fell 7 per cent on Friday after it said manipulation of the timing of options meant it would have to restate earnings going back to at least 2003, and the impact would be significant.