TOKYO -- A format war is brewing between two competing successors to DVD. In late November, four major studios -- Universal, Paramount, Warner and New Line -- said they would endorse the HD DVD format from Toshiba Corp., based here. The competing Blu-ray format is owned by a consortium that includes Sony Corp. and Matsushita Electric Industrial Co. Twentieth Century Fox and the labels owned by Sony, such as Columbia and TriStar, all back Blu-ray. The first HD DVD products are expected late next year.