A day after Toshiba delivered the deathblow to HD DVD, Amazon.com said Wednesday that it would throw its marketing weight behind the rival Blu-ray high-definition format.

Toshiba, which had led the charge for HD DVD against Sony-backed Blu-ray, gave up the fight Tuesday, saying it would stop shipping HD DVD players by the end of March. Amazon's decision followed similar announcements by major retailers Wal-Mart and Best Buy, and Hollywood distributor Warner Bros. Home Entertainment Group, which accounts for 20% of DVD sales in the United States.

Peter Faricy, VP of movies and music at Amazon, said the largest online-only retailer would more prominently promote Blu-ray hardware and software products in order to provide customers with "guidance on how to make the best high-definition buying decisions." Blu-ray movie titles have accounted for three-quarters of Amazon's high-definition sales since early January.

"In order to best serve our customers, Amazon is recommending Blu-ray as the preferred digital format and will continue to carry the 'Earth's Largest Selection' of Blu-ray products," Faricy said in statement.

While HD DVD movies and players will be downplayed on the site, Amazon will still continue carrying those products. Fire sales of HD DVD players have already been reported, with devices selling as low as $99. The players may be worth the price, given that they can play standard DVDs at a higher quality than regular players.

Companies that dropped support for HD DVD said it was necessary to eliminate customer confusion over having to choose between two competing and incompatible technologies. Most consumers have shunned high-definition DVDs and players to avoid being on the losing end of the format war, which was reminiscent of the battle between Betamax and VHS in the early days of videocassette recorders. VHS eventually won over Sony-backed Betamax.

One of the key reasons Sony won the format war was the inclusion of a Blu-ray disc player with the PlayStation 3. Sony sold more than 2.5 million PlayStation 3s last year, according to the NPD Group.

Microsoft continues to support HD DVD through a player it sell as an add-on for the Xbox 360 videogame console, which competes against the PlayStation. Microsoft has said it's too early to reveal its plans for HD DVD support.