LOS ANGELES (AP) -- Academy Awards voters will have to catch most of their movies on the big screen after Hollywood implemented a plan Tuesday to ban special DVDs and videotapes of Oscar contenders.

Fearing that ``screener'' copies could be used by video bootleggers to mass produce pirated DVDs and tapes, the major studios and their trade group, the Motion Picture Association of America, worked out an agreement.

``We know these screeners are a small part of piracy, but I aim to close every kind of hole in the dike I can find on piracy,'' Jack Valenti, head of the MPAA, told The Associated Press.

The agreement would include MPAA's seven studio members _ Disney, Warner Bros., Sony, Universal, 20th Century Fox, Paramount and MGM _ plus their affiliates such as New Line, Miramax, Focus Features and Sony Pictures Classics. DreamWorks, though not an MPAA member, also agreed to the screener ban.

Critics _ mainly executives for studio-owned film banners that distribute smaller, independent-minded pictures such as recent Oscar winners ``The Pianist'' and ``Pollock'' _ say the plan will cripple awards prospects for their movies.

Videotapes and DVDs of potential Oscar films have become commonplace during awards season as studios try to make sure as many of the 5,600 Oscar voters as possible see their movies.

Opponents of the ban say screener copies help level the playing field between high-profile studio flicks and smaller movies that lack big budgets for theatrical screenings aimed at Oscar voters and ads in Hollywood trade papers to promote the films.

The plan also would benefit truly independent distributors such as Lions Gate, Newmarket or IFC Films, which have no corporate links to MPAA studios and are not bound by the ban.

``If implemented the way it's being discussed, it will be one of the greatest boons to some of the more freelance companies,'' said James Schamus, co-president of Focus Features, the Universal banner that released ``The Pianist.''