Los Angeles, Jan 4 - "Avatar", the most expensive film ever, could also be on track to be the most successful as it broke the $1-billion mark at box offices worldwide over the weekend.

Since its opening last month, the 3D sci-fi spectacular has taken in $352.1 million in North America alone and $1 billion worldwide.

This weekend, Avatar added another $68.3 million in North American box offices, setting a new record for a film in its third week. That record had previously been held by Spider-Man with $45 million.

If Avatar is to become the most successful film of all time it will have to beat the last blockbuster by its director James Cameron. Titanic remains at the top with $1.8 billion at the box office. (dpa)