LOS ANGELES, Jan. 11 (Xinhua) -- The movie "Avatar" retained its U.S. box-office king position for the fourth consecutive weekend with another haul of 50.3 million U.S. dollars, according to the box office figures released on Monday.

    "Avatar" tells the story of an ex-Marine who finds himself thrust into hostilities on an alien planet filled with exotic life forms.

    The weekend amount made "Avatar" 2009's top-grossing movie with430.8 million dollars in four weeks.

    The total worldwide revenue of James Cameron-directed 3-D fantasy was estimated at more than 1.3 billion dollars.

    "Sherlock Holmes" remained in the second place for the third straight week on the top-grossing movie list, earning another 16.58 million dollars, to swell its North America earnings to 165.1 million dollars.

    Third on the list was "Alvin and the Chipmunks: The Squeakqual" with 16.56 million dollars, followed by "Daybreakers" with 15.1 million dollars and "It's Complicated" with 11.0 million dollars.

    The romantic comedy "Leap Year" opened in the sixth place with 9.2 million dollars, trailed by "The Blind Side" (7.5 million dollars), "Up in the Air" (7.1 million dollars), "Youth in Revolt"(6.8 million dollars) and " The Princess and the Frog" (4.6 million dollars).

    The dozen top-grossing movies generated a combined 148.5 million dollars over the weekend, up 15.89 percent from the 128.1 million dollars earned by the 12 top films during the same period a year ago.