The Mitsubishi group and DaimlerChrysler AG plan to jointly develop fuel cells with the aim of producing pollution-free motor vehicles, sources close to the project said Wednesday.

DaimlerChrysler, which gained a controlling stake in Mitsubishi Motors Corp. last year, has been pushing joint research with Nippon Mitsubishi Oil Corp. to develop sophisticated fuels to power next-generation motor vehicles.

The latest fuel-cell alliance will receive help from Mitsubishi Heavy Industries Ltd., which has been developing environmentally friendly technologies with MMC, and other allies, the sources said.