Actor Geoffrey Rush poses on the red carpet before the European premiere of "The King's Speech" in Leicester Square, London October 21, 2010.[Photo/Agencies]

The British film rating agency on Thursday revised its classification of "The King's Speech," making the movie starring Colin Firth as George VI a "12A" after its distributors complained about the "15" rating.

A "15" rating means the movie is deemed suitable for people who are 15 years or over, and can significantly limit box office potential. A "12A" rating is for movie goers of 12 years old or more.

The film, which has generated considerable pre-Oscars buzz and is due for theatrical release in Britain on January 7, 2011, will come with advice to viewers that it "contains strong language in a speech therapy context."

The British Board of Film Classification (BBFC) said that there were two "isolated instances" where Firth's character used repeated strong language at the instigation of his speech therapist in order to help him overcome a crippling stammer.

"The strong language is not aggressive and not directed at any person," the BBFC said in a statement.

"After careful consideration ... the (BBFC) board took the view that the way the strong language is presented in 'The King's Speech' did not contravene the language guidelines at '12A' and that the public would understand why the board has reached this decision."

The decision came shortly after the film's director, Tom Hooper, had expressed his frustration at the 15 rating.