Analysts are questioning the reasons behind further delays in the launch of Sony's eagerly-anticipated PlayStation 3 video games console.

Sony will push back the release of the PS3 to November, the company announced at a press conference in Tokyo today.

However, some analysts have questioned the reported reason for the delay, which Sony claims is due to problems with the digital rights management (DRM) on the console's next-generation Blu-ray optical drive. Instead, they suggest more serious issues.

"We think that slower than planned progress in developing the graphics chip, or a lack of software titles, is probably the main reason for the delayed launch," said analyst Eiichi Katayama of Nomura Securities' Financial & Economic Research Center in Tokyo.

Blu-ray discs will give the new PlayStation console removable storage capacity more than five times greater than that offered by the DVDs used in older consoles.

The Blu-ray DRM technology is already close to finalisation, Nomura believes, and is therefore an unlikely source of delays.

"Of the three copy protection technologies for the Blu-ray disc, AACS was set in the early stages of development, licensing of the ROM mark has already started, and licensing of BD+ is also likely to start soon," said Katayama.

"In view of this, we think that delays in copy protection technologies are unlikely to be the biggest reason for the delay in the PS3 launch."