Toshiba is to start making products that can play Blu-ray discs.
The decision marks a big change for the electronics firm which was the prime mover of the rival HD-DVD format.
Blu-ray and HD-DVD went head-to-head to see who could dominate the burgeoning market for movies produced in the high definition format.
The format war was effectively won in early 2008 when the Blu-ray camp won the backing of all four of the biggest movie studios.
Blu-ray was largely developed by Sony. Its efforts to dominate the HD market were also helped by sales of the PlayStation 3 which has a Blu-ray player built-in.
Toshiba said it would begin production of stand alone Blu-ray players as well as drives for PCs and laptops. Its first products are likely to be ready for the end of 2009.
The Japanese firm also said it would join the Blu-ray Disc Association (BDA) - the industry body which oversees development of the high-definition format.
"In light of recent growth in digital devices supporting the Blu-ray format, combined with market demand from consumers and retailers alike, Toshiba has decided to join the BDA," the Japanese firm said in a statement.