Toshiba Corp. and NEC Corp. said Thursday they have jointly developed a new format for next-generation DVDs that will enable manufacturers to continue using existing DVD production facilities, thus minimizing investment costs.

The companies plan to propose the new format to the DVD Forum, an industry association that promotes global DVD formats, company officials said.

DVDs are high-density compact discs that can store large amounts of data, including high-resolution audiovisual material.

The move is expected to spark a DVD format war as nine other electronics firms, including Sony Corp. and Matsushita Electric Industrial Co., already use a different format for next-generation DVDs.

The format proposed by Toshiba and NEC boosts the capacity of a single-sided, dual-layer and rewritable disc to a maximum of 40 gigabytes, enabling storage of high-definition digital images.

That would be more than four times the capacity of current DVDs, but it would fall short of the maximum 50 gigabyte capacity of the next-generation discs used by the nine other companies.

NEC is considering producing the new DVDs as early as next year for data storage in personal computers. Toshiba is also considering developing DVDs for displaying and recording images on PCs.

Among the seven other companies that use the alternative next-generation DVD format are Hitachi Ltd., Pioneer Corp., Royal Philips Electronics of the Netherlands, and Samsung Electronics Co. of South Korea.

Currently, there are three incompatible formats for DVDs. Experts expect next-generation DVDs will also be divided into different formats.