Federal prosecutors in Philadelphia have filed charges against the CEO and other executives at National Lampoon Inc., accusing the executives of trying to artificially inflate the company's stock price.

Los Angeles-based National Lampoon is the publicly traded company that owns the rights to the "Vacation" and "Animal House" series of films, among others.

Prosecutors on Monday filed three indictments and an information charging seven people with conspiracy and securities fraud.

Prosecutors say the company manipulated prices by paying kickbacks to people to buy and hold stock. Authorities say that activity created the illusion of market interest.

Officials say many of the defendants had significant stock holdings and stood to gain millions of dollars.

Marcy Goot, a company spokeswoman, declined immediate comment.