Nippon Mitsubishi Oil Corp said yesterday that it and DaimlerChrysler AG would jointly conduct trials in driving fuel-cell powered vehicles in Japan by the 2000/01 business year. The companies announced earlier that they have agreed to jointly conduct studies on ways to popularise the use of fuel-cell powered vehicles. A spokesman for Nippon Mitsubishi, Japan's largest oil refiner and distributor, said that it would able to contribute in developing fuel to be used in the environment-friendly power system as well as in building infrastructure for suppling the fuel.