LOS ANGELES ? Science-fiction adventure "Avatar" topped the North American box office this weekend, scooping $77 million in a stellar debut for the effects-laden epic, final figures showed Monday.

Director James Cameron's first film since the 1997 Oscar-winner "Titanic" is a 3-D spectacular with a reported budget of $300-500 million, which would make it the most expensive movie ever.

The film, a love story set on a distant planet, accounted for about 59 percent of the weekend box office, according to industry tracker Exhibitor Relations.

Analysts believe "Avatar" would have scored an even bigger opening had it not been for the winter storm that dropped record snowfalls on large areas of the eastern United States, deterring movie-goers from theaters.

Avatar dislodged Disney's "The Princess and the Frog," which earned $12.2 million for second place.

Third was "The Blind Side," a drama about a white couple who give an illiterate black teen a home and a new lease on life. The film scored $10 million in its fifth week of release.

Next was "Did You Hear About the Morgans?", a romantic comedy in which Hugh Grant and Sarah Jessica Parker play an estranged couple who witness a mob hit and are placed in a witness protection program. The film grossed $6.6 million in its debut.

Fifth place went to "The Twilight Saga: New Moon," the vampire romance sequel adapted from Stephenie Meyer's phenomenally successful books, with $4.4 million.

In sixth spot with $4.2 million was "Invictus" starring veteran actor Morgan Freeman, about how then-president of South Africa Nelson Mandela united the country around the 1995 World Cup.

Seventh place went to "Disney's A Christmas Carol," starring wacky comedy hero Jim Carrey with earnings of $3.4 million.

Eighth was "Up In the Air" starring George Clooney in the acclaimed story of a corporate downsizer who starts to question his role in life, which earned $3.2 million.

"Brothers," a drama starring "Spider-Man" Tobey Maguire about the impact of the Afghanistan war on a conflicted US family, which earned $2.9 million in its fourth week of release, was next.

"Old Dogs," a Disney film starring John Travolta and Robin Williams, earned $2.3 million to round out the top 10 films.