US box office chart

1. Jurassic Park III 2. America's Sweethearts 3. Legally Blonde 4. The Score 5. Cats and Dogs

American Sweethearts - Julia Roberts and Catherine Zeta-Jones' Hollywood satire - was second in the chart, taking $31m (�21.8m) according to initial studio estimates.

But Spielberg's other recent major project, AI, has not lived up to expectations, dropping out of the top 10 after just four weeks on release.

Some had predicted that Jurassic Park III would not fare as well as the previous two instalments, without Spielberg at the helm and missing star Jeff Goldblum.

Crystal, Zeta-Jones and Roberts star in America's Sweethearts

But it beat the opening weekend total of the original Jurassic Park, which made $50.2m when it was released in 1993.

The Lost World: Jurassic Park II opened with $72m (�50.5m) in 1997.

The latest instalment sees Sam Neill, T�a Leoni and William H Macy once more chased around a remote island by resurrected dinosaurs.

It was directed by Joe Johnston, who was also in charge of Jumanji and Honey, I Shrunk The Kids.

It opened at US cinemas on Wednesday, taking $80.9m (�56.8m) in its five days since release, and $50.3m since Friday.

America's Sweethearts, released on Friday, stars Roberts as sister and trusted aide to insecure movie star Zeta-Jones.

AI was originally a Stanley Kubrick project

Roberts, who wore a fat suit for most of the film, plays the ugly duckling and doormat to her sister's incessant demands.

The romantic comedy also stars Billy Crystal and John Cusack, and is released in the UK in October.

AI, which stands for Artificial Intelligence, topped the box office chart when first released at the beginning of July, but has now slid out of the top 10.

It was taken on by Spielberg after the project's champion, A Clockwork Orange and Eyes Wide Shut director Stanley Kubrick, died.

Also dropping down the list is Final Fantasy: The Spirits Within, an animated feature heralded as one of the most advanced ever.

It was released in America on 11 July - but has now slid to number eight in the chart, having taken a total of $26.7m (�18.7m) since its release - despite a reported budget of $137m (�96m).