Wal-Mart has become the latest company to adopt Blu-ray exclusively for high-definition DVDs.

The retail giant said in a statement on Friday that it will begin a three-month phase-out of its HD-DVD titles.

Users should not begin to notice the transition for another 30 days, when the effort will begin in earnest. By June, all Wal-Mart and Sam's Club stores will stock only Blu-ray movies.

The company said that the move was largely due to poor HD-DVD sales. "Our customers are showing a clear preference for Blu-ray products and movies," said Gary Severson, senior vice president of Wal-Mart's home entertainment division.

"With the customers' best interests in all we do, we wanted to share our decision and timeline with them as soon as possible, knowing it will help simplify their purchase decision, increase selection and increase adoption long term."

Wal-Mart's decision deals a major blow to Toshiba and its backers in the HD-DVD camp, which continue to battle Sony and Blu-ray for control of next-generation high-definition DVD discs.

Rumours circulating this morning suggest that Toshiba may be preparing to end to its support for HD-DVD.

The Wal-Mart announcement wraps up a week of victories for Blu-ray. Film rental service Netflix vowed to carry Blu-ray discs only, and retail chain Best Buy said that it would push Blu-ray to customers as its "preferred" format.

The three major distributors join recent Blu-ray converts such as Warner Bros, which is to abandon HD-DVD and distribute its titles exclusively in Blu-ray.