Disney announced yesterday that it would release its films on Sony's Blu-ray DVD format - a week after three other Hollywood studios backed rival Toshiba's HD-DVD.

The battle between the two formats, reminiscent of the 1980s fight between Betamax and VHS for control of the videotape format, will determine which product cinema fans will have to buy to view future releases.

Disney said it is backing Sony because Blu-ray offers higher quality and was backed by most consumer electronics manufacturers. But Warner, Universal and Paramount are supporting Toshiba's HD-DVD product because they say it offers better anti-piracy guarantees.

"The reality is that this format war is not going to be won by content alone but in combination with the support from the DVD player manufacturers, who by sheer number vastly support the Blu-ray format," said Bob Chapek, president of Disney home video division Buena Vista Home Entertainment, to the Hollywood Reporter.

Until yesterday, the Blu-ray camp had no official backing from any Hollywood major studios, apart from its own Columbia and MGM companies.

20th Century Fox has yet to make a decision on which format it will use.

In the manufacturers' camp, more than 90 consumer electronics companies, including Matsushita, Phillips, Thomson and PC makers Dell and Hewlett-Packard, are backing Blu-ray. But Sanyo and NEC are backing HD-DVD.

Both products promise higher storage capacity, superior image quality and stronger anti-piracy protection.