The Japanese unit of Microsoft Corp. said on Monday the company's next-generation operating system, Longhorn, would be compatible with HD DVD, an advanced form of DVD technology. The show of support from Microsoft is considered a boost for the next-generation, blue-laser DVD technology, which is promoted by Japanese conglomerates NEC Corp. and Toshiba Corp.

Blue light, with a shorter wavelength than the red laser used in conventional DVD recorders, can read and store data at the higher densities needed for high-definition recordings.

An executive at Microsoft's Japanese unit said at a briefing on HD DVD technology that it was not yet decided whether Longhorn, the next version of Windows, would support the rival Blu-ray technology from a consortium of companies, including Sony Corp (NYSE:SNE - news) (news - web sites). and Philips Electronics.

The HD DVD camp is far behind the Blu-ray group when it comes to actual product offerings.

Sony last year launched the world's first DVD recorder using blue laser light, while Matsushita Electric Industrial Co. Ltd., the maker of Panasonic products, plans to start offering a DVD recorder based on Blu-ray technology this week.

DVD recorders based on the HD DVD format have yet to hit store shelves, but Toshiba Corporate Senior Vice President Yoshihide Fujii said the company planned to launch them sometime in calendar 2005. He would not comment on expected retail prices.

At the briefing, Pony Canyon Inc, a music, video and game software unit of radio station Nippon Broadcasting System Inc., said it planned to launch a series of movies in the HD DVD format next year, becoming the first content creator to commit itself to offering HD DVD-based content.