TOKYO - Japan's Toshiba Corp. said Wednesday that it has developed the technology to mass-produce recordable high-definition DVDs. The advance is the latest step in a heated global race to establish a world standard for the next-generation of optical disks, which are expected to offer sharper images than current DVDs. Toshiba said the new technology, developed jointly with Mitsubishi Kagaku Media Co. and Hayashibara Biochemical Laboratories Inc., will enable the manufacture of single-recording HD-DVD disks with 15-gigabyte storage capacity. Disc manufacturers, currently producing recordable DVD disks, will only have to make minor modifications to be able to produce the new higher-definition kind, Toshiba said. Optical disc makers Hitachi Maxell Ltd. and Mitsubishi Kagaku said they will market the new HD-DVD-R discs next spring, when Toshiba plans to launch HD-DVD recorders. In the battle for a high-definition successor to DVDs, there are two technologies competing to become the world standard. Toshiba leads a group that backs the HD-DVD format, while Sony Corp (SNE.N). leads a rival group promoting the Blu-ray Disc format. Blu-ray have more capacity with 50 gigabytes compared to 45 gigabytes for HD-DVD read-only disks, but proponents of HD-DVD say their format is cheaper to make because the production method is similar to current DVDs.