Already fingered by analysts as a potential stock options backdater and sued by shareholders over its past grants, Activision ( ATVI) is now the subject of a Securities and Exchange Commission probe over its options practices. The video game software publisher announced after the bell on Friday that the SEC has notified the company that it has launched an informal inquiry. Activision "intends to cooperate fully and respond to the SEC's inquiry," the company said in a regulatory filing. Additionally, the company has begun its own internal investigation into its past options practices, Activision said in the filing. The internal probe will be headed up by several unnamed independent members of its board. The company didn't say whether the SEC or the internal probe will investigate the backdating allegations made against the company, only that they are looking into the company's past options practices. Shareholders sold off the stock in regular trading on Monday. In recent trading, shares of Activision were down 72 cents, or 5.8%, to $11.75. Stock options were long the currency of choice among high-tech companies, which often gave them to employees instead of cash. Options give employees and executives the right to buy the company's stock at a preset price, typically the market price of the stock on the day they are granted to the employees. However, dozens of companies are now being investigated for handing out options that carried a strike price that wasn't equal to the market price on the grant date. Instead, these companies are accused of picking a past market price that was known at the time to have been a short-term low in the companies' stocks as the strike price for the options. The practice gave the options an inherent -- not just projected -- value at grant.