Paramount is poised to drop its support of HD-DVD following Warner Brothers' recent backing of Sony's Blu-ray technology, in a move that could sound the death knell of HD-DVD and bring the home entertainment format war to a definitive end.

Paramount and DreamWorks Animation, which makes the Shrek films, came out in support of HD-DVD last summer, joining General Electric's Universal Studios as the main backers of the Toshiba format.

However, Paramount, which is owned by Viacom, is understood to have a clause in its contract with the HD-DVD camp that would allow it to switch sides in the event of Warner backing Blu-ray, according to people familiar with the situation.