Los Angeles ? James Cameron’s “Avatar” continues to race up the box office charts, remaining No. 1 domestically for the fourth straight weekend with $48.5 million and placing second among all-time top-grossing films worldwide.

The science-fiction saga from 20th Century Fox added $143 million overseas to raise its international haul to $906 million. With $429 million domestically, “Avatar” has pulled in $1.34 billion worldwide, behind only Cameron’s “Titanic,” which took in $1.8 billion.

In just 24 days, “Avatar” shot past the $402.1 million domestic total of “Transformers: Revenge of the Fallen” to become the No. 1 release of 2009. Cameron’s tale of humans and aliens in conflict on a distant world now stands at No. 6 on the all-time domestic chart.

The film has just over $100 million to go to pass the No. 2 domestic hit, “The Dark Knight” at $533.3 million.

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theaters, according to Hollywood.com:

1. “Avatar,” $48.5 million.

2. “Sherlock Holmes,” $16.6 million.

3. “Alvin and the Chipmunks: The Squeakquel,” $16.3 million.

4. “Daybreakers,” $15 million.

5. “It’s Complicated,” $11 million.

6. “Leap Year,” $9.2 million.

7. “The Blind Side,” $7.8 million.

8. “Up in the Air,” $7.1 million.

9. “Youth in Revolt,” $7 million.

10. “The Princess and the Frog,” $4.7 million.