Plans for the governments and private sector companies of Japan, South Korea and China to jointly work together on the development of a new operating system to rival Microsoft Corp.’s Windows will be unveiled later this week, according to two Japanese newspaper reports.

Takeo Hiranuma, the Japanese Minister for Economy, Trade and Industry, will outline the plan at a regional meeting of economic ministers in Phnom Penh, Cambodia, on Wednesday, reported the Nihon Keizai Shimbun in its Sunday edition and the Asahi Shimbun on its Web site on Monday.

The Japanese Ministry of Economy, Trade and Industry declined to confirm the report.

The Wednesday announcement will be the first time that the plans will be made public. The final agreement on the project is due in the middle of September, the reports said.

The focus of the work was unclear from the newspaper reports.

The Nihon Keizai Shimbun, quoting “sources close to the matter,” said a new operating system was being considered after the recent spate of viruses that has targeted the Windows operating system. Work to be undertaken will include development of new applications such as word processor and spreadsheet software.

In its report, the Asahi Shimbun said the plan is aimed at “smart devices” such as cellular telephones, digital cameras and car navigation systems and computer servers. The idea is being driven by a fear that Microsoft could corner the market for such devices as it has done on the desktop, said the Asahi.

Both newspapers agreed that the project would take the open-source Linux operating system as its base and build on top of it.

Japanese companies including NTT Data Corp., Matsushita Electric Industrial Co. Ltd., NEC Corp., Hitachi Ltd. and Fujitsu Ltd. are expected to take part, said the Nihon Keizai Shimbun.