HP, a one-time staunch supporter of Blu-ray technology, yesterday hedged its bets in the next-generation high definition disc format race by joining the HD-DVD Promotions Group.

The vendor had supported the Blu-ray format exclusively, but said that its latest move was "to provide consumers with the best possible high-definition experience".

HP's relationship with the Sony-led Blu-ray camp had been strained recently when Sony refused to adopt a technology proposal from HP.

HP had requested that the Blu-ray Disc Association adopt two technologies, Mandatory Managed Copy and iHD, both of which are already included in the HD-DVD format.

Mandatory Managed Copy, which permits consumers to make legal copies of video content, was formally adopted by the Blu-ray Association. iHD, which allows enhanced interactivity on next-generation DVDs, and coincidentally has already been tapped for integration into Windows Vista by Microsoft, was not approved for launch.

While the Blu-ray group's refusal to adopt iHD may have put HP's nose out of joint, HP's move to support both technologies makes the prospect of a standards war more likely.

"By joining the HD-DVD Promotions Group and continuing to work with the Blu-ray Disc Association, HP will be in a better position to assess true development costs and, ultimately, provide the best and most affordable solution for consumers," HP said.

However, the Blu-ray supporters managed to get one up on the HD-DVD camp this week, when TDK announced that it has commenced shipping mass production samples of Blu-ray discs in no fewer than four different flavours.

The vendor is shipping write once and RW single sided, single layer, 25GB capacity discs, and write once and RW single sided, dual layer discs in 50GB capacity. All discs will feature the hardened Durabis 2 type coating, the company said.