Microsoft and Intel have decided to back HD-DVD, the next-generation DVD format being developed by the DVD Forum, the companies said in a joint statement on Monday.

Microsoft and Intel announced their support for HD-DVD by joining the HD-DVD Promotion Group, an industry organisation set up to promote adoption of the optical disc format. Other members of the group include electronics makers such as NEC, Sanyo and Toshiba, as well as content providers including Universal Studios and Paramount Pictures.

Microsoft’s decision to back HD-DVD marks a change of direction for the company, which had previously said it wanted to remain neutral in the battle between the dueling HD-DVD and Blu-ray Disc formats.

“Although the companies have determined that HD-DVD is the only viable solution at this time, each remains committed to working toward one format that meets consumer and industry requirements,” Microsoft and Intel said in the statement.

The announcement pits Intel and Microsoft against several important customers in the duel over optical disc formats. A larger number of companies have so far thrown their support behind Blu-ray Disc, including Sony, Panasonic, Samsung, Dell, HP, Apple and Philips.