American screen writers have voted celluloid classics Citizen Kane and Casablanca the best movie scripts ever - but the most over-rated.

A survey by the publishing house Library of America found that Citizen Kane, co-written by Orson Welles and Herman J Mankiewicz, was rated the top screenplay in movie history.

Casablanca, written by Julius and Philip G Epstein and Howard Koch, was second.

But both films also appeared in the top four of most over-rated screenplays.

Oscar-winners

Number one in the most over-rated list was Quentin Tarantino's Pulp Fiction, followed by Citizen Kane and, at number four, by Casablanca.

All three were Oscar-winning screenplays.

The Library of America sent surveys to 4,500 members of the Writers Guild of America, the union representing screenwriters.

The publisher is using the results to help decide what to include in an anthology series of notable film scripts it plans to start in 2003.

Also in the top five scripts were The Godfather, Chinatown and All About Eve.

'Over-rated choices'

Max Rudin, the publisher of the Library of America, suggested Citizen Kane and Casablanca appeared on the most-over-rated list because many writers were reacting against obvious film choices that draw attention away from lesser-known works.

"The motives for the over-rated choices are a mixed combination of contempt bred from familiarity and, I think, envy in some cases," said Mr Rudin.

The Library of America also used the survey to compile a list of five underrated screenplays.

They were Groundhog Day, Quiz Show, Aliens, The Wizard of Oz and The Best Years of Our Lives.