The Covenant 'opened within expectations', Sony Pictures said

The Covenant, which sees pupils trying to destroy each other at an exclusive boarding school, earned $9m (�4.8m).

Hollywoodland, a drama dealing with the death of George Reeves, who played Superman on TV in the 1950s, came second with $6m (�3.2m).

Last week's number one, US football drama Invincible, fell to third.

It took $5.8m (�3.1m), while the new entry at four - The Protector, with martial arts star Tony Jaa - generated $5m (�2.7m).

Violent thriller Crank was down three places to number five and earned $4.8m (�2.6m).

NORTH AMERICAN BOX OFFICE 1. The Covenant 2. Hollywoodland (pictured) 3. Invincible 4. The Protector 5. Crank 6. The Illusionist 7. Little Miss Sunshine 8. The Wicker Man 9. Talladega Nights: The Ballad of Ricky Bobby 10. Barnyard: The Original Party Animals Source: Exhibitor Relations

The Covenant recorded the worst opening week of any North American chart-topper since the release of Dickie Roberts: Former Child Star.

The comedy, about a TV personality who believed he never had a childhood, made $6.6m (�3.5m) in 2003.

And the revenue generated by The Covenant was less than a third of The Exorcism of Emily Rose, the film which held the number one position during the same weekend last year.

The past weekend marked the beginning of the autumn season, which was "starting off a little slow", conceded Paul Dergarabedian, the president of cinema tracking company Exhibitor Relations.

"I don't think anyone expected this weekend to set the world on fire in terms of box office," he told the AP news agency.

On Friday, the biggest hit of the summer - Pirates of the Caribbean: Dead Man's Chest - passed the $1bn (�536m) mark.