The Hollywood studio behind this year's blockbuster, The Dark Knight, has launched an ambitious campaign to dominate the coming Academy Awards and score Heath Ledger a posthumous Oscar.

Warner Bros this week rolled out its first Oscar specific ad, a "For Your Consideration" poster aimed at members of the Academy as well as voters of the key lead-in award ceremonies, the Golden Globes, Screen Actors Guild and Directors Guild of America.

The studio has also set up a special website to lure awards voters.

The site, www.warnerbros2008.com, is dedicated to the studio's top two Oscar hopes, The Dark Knight, and the drama Gran Torino, directed by and starring Academy favourite, Clint Eastwood.

It encourages awards voters to see special free screenings of the two films in the four cities where most Academy members live, Los Angeles, New York, San Francisco and London.

"Please bring your Guild card," Warner Bros urges Academy voters and members of the acting, directing, cinematography and other guilds.

The website also leads voters to links to two positive columns in influential American publications, Variety and Entertainment Weekly, that call on the Academy to shrug off perceived bias against comic book adaptation and fantasy films.

History shows the Academy awards smaller independent films, rather than box office behemoths.

In the Variety column, Ledger's performance as The Joker in The Dark Knight is compared to another actor who scored an Oscar for playing a villain, Anthony Hopkins, who won in 1992 for serial killer Hannibal Lecter in The Silence of the Lambs.

"Comparisons to Anthony Hopkins' Oscar-winning turn in The Silence of the Lambs are not inappropriate; like Hannibal Lecter, this Joker is an eloquent psychopath who manages, in very little screen time, to foster a disquieting intimacy with the audience," Variety's Justin Chang wrote.

If The Dark Knight snares best picture or Ledger or one of his castmates pick up an Oscar, it will be history-making as the Academy's 6,000 members have never shown much love for comic book adaptations.

There has also been a perceived snobbery among Academy voters to the films that draw the biggest box office, with Peter Jackson's The Lord of the Rings: The Return of the King in 2004 a rare best picture winner and box office number one.

The fantasy epic earned $US1.1 billion ($A1.69 billion) in ticket receipts, the second highest take in film history, and went on to win 11 Oscars, including best picture.

However, not one actor was handed an award.

The Dark Knight, so far with a worldwide box office take of $US995 million ($A1.53 billion), has a realistic chance to eclipse Return of the King by the end of the year and sit in second place behind all-time box office king, 1997's Titanic and its $US1.8 billion ($A2.76 billion) haul.

Entertainment Weekly columnist Mark Harris pleaded with the Academy to not discriminate against The Dark Knight.

"Don't dismiss it just because it's a comic-book movie," he wrote.

"True, the genre lacks Oscar experience.

"But this comic-book movie has shown judgment and maturity in a year when many veteran genres have felt erratic.

"Why not make some history?

"Even within the Academy, there's a first time for everything."

Perth-born Ledger died in January aged 28 from an accidental overdose of prescription drugs and if he wins the best supporting actor Oscar, he will become the first actor since Network's Peter Finch in 1977 to win an Academy Award from the grave.

The 81st Academy Awards will take place at Hollywood's Kodak Theatre on February 22.