Three major film studios have been unwilling so far to ink deals that would let YouTube rent out their movies, a new report claims.

Rumors surrounding YouTube's plans to expand its rental service with flicks from major studios most recently cropped up earlier this week. As of this writing, Warner Bros., Sony Pictures Entertainment, and Universal Studios have all signed on, according to reports.

However, Fox, Disney, and Paramount Pictures have decided against signing a deal with YouTube, according to an article published yesterday by TheWrap, an entertainment-news site. The article claims the studios are holding out over concerns that YouTube still features too much pirated content. They're ostensibly using their content as a key bargaining chip.

YouTube launched its rental service last year. The services lets people rent movies from non-major studios for about $2.99. YouTube told CNET in a statement today that its rental service currently has "thousands of titles available." The company also offers ad-supported movies on the site, thanks to partnerships with content partners.

Piracy issues or not, the chances of Google getting Paramount to sign a deal are practically nil. That's because the studio is owned by Viacom, which filed a $1 billion lawsuit against Google-owned YouTube in 2007, claiming that YouTube allowed, and even encouraged, people to commit intellectual property theft.

Last June, a U.S. District Court judge struck down Viacom's suit, saying that Google was "protected by the safe harbor of the Digital Millennium Copyright Act."

Viacom filed an appeal in August challenging the court's ruling, leading to speculation that the case could continue for years to come.

YouTube declined to comment on the possibility of bringing films from major studios to its rental service.