Japan has quietly signed an agreement with Germany that will open the door for cooperation on defense technology development.

At Germany's request, no formal announcement was made.

However, several government sources confirmed that the agreement on the transfer of defense equipment and technology had been signed in Berlin between Ambassador Takeshi Yagi and Katrin Suder, a state secretary in the German Defense Ministry.

The agreement is the eighth of its kind for Japan. The United States, France and Britain are among countries with which Japan has similar pacts.

According to Defense Ministry sources, the agreement will give Japan the means to develop faster tanks that can serve as troop transport carriers for use by the Ground Self-Defense Force in Japan's outlying islands. Germany's tank technology is highly regarded.

The agreement falls under revised principles on the transfer of defense equipment that allows Japan to jointly develop defense technology under certain conditions.

Those principles obligate partner nations to strictly manage information with regard to weapons capability, such as when using the technology for purposes other than the original objective or passing on the information to third parties.

The principles also call for transparency when sharing the information. That raised concerns within the Defense Ministry about a possible public backlash as Germany had long insisted that the agreement not be formally divulged.

The accord reflects Japan's policy of improving defense technology cooperation with European nations. Japan signed a defense equipment and technology transfer agreement with Italy in May and has also begun joint research with Britain designed for missile development.