OMAHA, Neb.--(BUSINESS WIRE)--(BRK.A; BRK.B) - Following the close of the markets in Japan today, Berkshire Hathaway's wholly-owned subsidiary, National Indemnity Company, will notify Japan's Kanto Local Finance Bureau that it has increased its ownership interest in five of the leading Japanese trading companies. The companies, listed alphabetically, are Itochu, Marubeni, Mitsubishi, Mitsui and Sumitomo. Presently these are the only publicly traded investments that Berkshire owns in Japan. Thei