Pixar's latest film The Incredibles tells of a family of superheroes

Both companies said they wanted to move the release date from November 2005 to summer 2006 to capitalise on children being on their school break.

Cars will be the final film produced by Disney-Pixar. Their distribution deal is due to end in 2005.

A spokeswoman for Disney denied the two were in talks about a further deal, prompting the delay.

'Perfect sense'

Steve Jobs, Pixar's chief executive, said: "Cars longs to be a summer movie.

"We plan to finish Cars on its original schedule, and look forward to Cars and our future films benefiting by summer theatrical releases and holiday DVD releases."

The announcement follows comments made by Mr Jobs last month when he said Pixar hoped Cars would replicate its success with Finding Nemo - a summer release that became the 12th highest grossing US movie of all time.

Dick Cook, chairman of The Walt Disney Studios, said the move made "perfect sense".

"In the vein of Finding Nemo, we feel the movie will have legs throughout summer and beyond," he said.

"Cars is the quintessential summer film for audiences of all ages.

"It has a fantastic story full of action, adventure, comedy, heartfelt emotion with cutting edge animation and incredible voice talent."

Profit share

Cars is an animated road movie by John Lasseter, the director of Pixar-Disney's other films Toy Story and A Bug's Life.

The Disney-Pixar partnership has also included Toy Story II, Monsters Inc, Finding Nemo and their current release The Incredibles, which has so far taken more than $226m (�118m) at the box office.

Under the current agreement, Disney gets half the box office profits plus a distribution fee from Pixar.

Pixar, which is already working on its next title, is still to negotiate a distribution deal with another studio.

The release of that untitled film has been pushed back from 2006 to 2007.