By Aidan Malley

Published: 05:35 PM EST

Movie studio Warner Bros. has confirmed that it will switch to releasing HD movies only in the Blu-ray Disc format, potentially ending HD DVD's run in the marketplace and affecting the computer industry as a consequence.

The Hollywood business says it will continue producing movies in the two next-generation disc formats until May of this year, when it will use Blu-ray alone. Regular DVDs will still be sold alongside the HD format.

Abandoning HD DVD is a difficult decision but a "strategic" one based on a shifting balance of power between the two disc standards, Warner says. Since more customers are buying Blu-ray titles, choosing the one standard may help decisions at store shelves. Prices for movie players are said to be low enough that encouraging competition between the rival standards is no longer necessary.

"The window of opportunity for high-definition DVD could be missed if format confusion continues to linger," Warner Bros. chief executive Barry Mayer explains.

Dropping the standard is expected to create a tidal shift in the balance between Blu-ray and HD DVD. While both formats have until now offered a similar amount of movies in their format, Warner's defection may place as much as 70 percent of all major-label HD movies in the Blu-ray camp.

The timing of the choice may prove crucial for Apple. Both analysts and AppleInsider sources have indicated the Mac maker is likely to fully endorse Blu-ray as early as this month's Macworld San Francisco Expo. The company is a member of the Blu-ray Disc Association but has also included basic HD DVD support in its video editing software.

Microsoft has so far put most of its weight behind HD DVD and has supported the medium both through an Xbox 360 add-on and by encouraging use of the format by PC makers.