The two remaining studios backing HD DVD, Universal and Paramount, could switch sides soon, ending the high-def format war instantly.

According to Variety, it has been confirmed that Universal's commitment to backing HD DVD exclusively has ended. And Paramount has an escape clause in its HD DVD contract allowing it to release pics on Blu-ray after Warner Bros.' decision to back that format exclusively.

Neither studio is ready to throw in the towel immediately, however. Universal is committed to a series of promotions for the high-def format in coming months, and Par has said its current plans are to keep supporting HD DVD, which it backed exclusively in August.

Should Toshiba concede defeat on the format, the decision to drop HD DVD would be made for both studios. But Toshiba doesn't appear ready to do that. At the Consumer Electronics Show, the manufacturer reaffirmed its commitment to the format, noting strong sales during the fourth quarter and indicating it would continue marketing its hardware through 2008.

But retailers may force the HD DVD camp's hand: They're unlikely to keep devoting premium shelf space to a dying format, and at this point, the odds are not in HD DVD's favor. With Warners' defection, only Par and U remain in the HD DVD camp; Sony, Disney, Fox, Lionsgate remain ardent Blu-ray backers. Warner sister companies New Line and HBO are also shifting allegiance to Blu-ray.

Last summer, Blockbuster also threw its weight behind Blu-ray, though some HD DVD discs remain in stores.

And Warner will continue to release HD DVD discs for the next few months to honor its previous commitment to Toshiba, which extends through May 31. Paramount's HD DVD deal, which covers DreamWorks releases, was to run through this year.