'Dark Knight' spends a month at No.1

The Dark Knight has maintained its grip on the US box office chart, spending a fourth consecutive week at number one.

The superhero film's $26 million gross edged out new entry Pineapple Express, which debuted to a solid $22.4 million, to take pole position at the weekend box office.

The other new wide release, Warner Bros' The Sisterhood Of The Travelling Pants 2, landed at number four with $10.7 million.

The Dark Knight is the first film since 2003's The Lord Of The Rings: The Return Of The King to hold the number one spot for a month.

Christopher Nolan's sequel is now in third place on the all-time US blockbuster list, with its $441.5 million total putting it behind Star Wars ($460.9 million) and Titanic ($600.7 million).

The top ten in full:

1. (1) The Dark Knight - $26,030,000
2. (-) Pineapple Express - $22,400,000
3. (2) The Mummy: Tomb Of The Dragon Emperor
4. (-) The Sisterhood of the Travelling Pants 2 - $10,770,000
5. (3) Step Brothers - $8,900,000
6. (4) Mamma Mia! - $8,081,000
7. (5) Journey To The Centre Of The Earth - $4,855,000
8. (7) Hancock - $3,300,000
9. (6) Swing Vote - $3,106,000
10. (8) WALL-E - $3,045,000