Corporate groups led by Sony Corp. and Toshiba Corp. are mulling joint development of a unified standard for next-generation DVDs, sources said Thursday.

The two rival camps, which have been promoting the competing standards Blu-ray and HD DVD, plan to reach an accord on a common standard by the end of this month, the sources said.

But sources close to the talks said that while both camps have agreed on the need for a unified standard, each is strongly pressing to have its own core technology chosen as the new standard. Both have pumped huge funds into research and development.