Mexican directorAlfonso Cuaron and his producing partner Jorge Vergara are demanding anoverhaul of the Mexican ratings system after Cuaron's current box office hit Y Tu Mama Tambien was slapped with a C rating, restricting it to local audiences aged 18 andabove.

Although commerciallylimiting, the C certificate has not stopped the raunchy comedy - about two teenageboys who embark on a sexual road-trip with an older woman - from breaking boxoffice records on its opening week in Mexico.

So far, the film has grossed $6.45m since its June 8th debut even though its two seventeen-year-old protagonists would presumably be barred from seeing their own exploits on the big screen. By comparison, the highest grossing Mexican film ever, Sexo,Pudor y Lagrimas, totaled$12.4m at the local box office.

Despite their success, Vergara and Cuaron, partners in their new production company Anhelo, have demanded to know the criteria by which the Direccionde Radio Television y Cinematografia (RTC) decided on the C rating.

"We are going to demand a new law which will instigate changes in the ratings systemand put a stop to the arrogance of some civil servants," said Vergara. Cuaronalso demanded to know the names and qualifications of the persons who decide onthe ratings, as this information should be made public.

At the very least, the controversy has stirred up debate on Mexico's antiquated ratings system which certifies films with in one of four labels: AA for Children's (mainly animated) films; A for GeneralAudience; B for Parental Guidance; and C for Restricted. While some punditsagree the system badly needs a revamp in light of its seeming arbitrariness, othermore cynical observers feel all this latest fuss is just a marketing ploy.

Released by 20th Century Fox, Y Tu Mama Tambien is Cuaron's first Spanish-language film after some timespent in Hollywood where he directed Fox's Great Expectations (1998) and Warner Bros' The Little Princess (1995). Cuaron co-wrote the script for Y Tu Mama Tambien (which is literally translated in English as And Your Mother Too) with his brother Carlos Cuaron.

Vergara is a highly successful Mexican businessman and arts patron whose company Omnilife is a Guadalajara-based supplier of nutritional supplements.

Cuaron and Vergara have retained distribution rights to North America, Latin America and Spain. They have since licensed all Latin American rights to 20th Century Fox and all rights in Spain to Sogepaq. IFC Films, the theatrical distribution arm of he Independent Film Channel, recently acquired North American rights. New York-based sales operation Good Machine International (GMI), has been handling sales of the sexually-charged film in remaining territories.