Chicken Little is Disney's first all-computer animated film

The cartoon fable took in $40.1m (�22.9m) between Friday and Sunday, according to studio estimates.

Jarhead, from Oscar-winning UK director Sam Mendes and starring Jake Gyllenhaal and Jamie Foxx, made $28.8m (�16.4m).

Last week's leader, gory horror sequel Saw II, dropped to number three after taking $17.2m (�9.8m).

The Legend of Zorro, which reunites Catherine Zeta Jones and Antonio Banderas, dropped two places to number four with takings of $10m (�5.7m), followed by the Meryl Streep and Uma Thurman comedy Prime, with $5.3m (�3m).

3D screening

Hollywood watchers were keen to see how audiences would receive Chicken Little.

US/ CANADA TOP FIVE 1. Chicken Little 2. Jarhead 3. Saw II 4. The Legend of Zorro 5. Prime Source: Exhibitor Relations

The film is the first all-computer animated movie Disney had made without the help of its partner Pixar.

The opening weekend take fell short of recent Disney/Pixar hits such as The Incredibles and Finding Nemo, which each made more than $70m (�40m).

But the debut was in line with other animations including Fox's Robots and DreamWorks' Shark Tale, said Exhibitor Relations, compiler of the box-office figures.

Disney and Pixar are currently in talks to renew their deal which is due to come to an end in 2006.

The Chicken Little takings included $2.1m (�1.2m) from 84 cinemas showing a 3D version of the film.