It looks like we have a winner in the fight to determine the dominant format for high-definition DVDs. The see-sawing battle tipped strongly to Sony’s Blu-ray last week when film studio Warner Bros announced it would stop releasing films in the rival HD format backed by Microsoft and Toshiba. Roughly 70 per cent of new movies will now be released exclusively on Blu-ray. Toshiba appeared to be in disarray at the critical Consumer Electronics Show in Las Vegas. Its shares dropped 2.3 per cent yesterday to their lowest level since March. Sony, which will now face less pricing pressure, was up 0.7 per cent in a falling Japanese market.