Warren Buffett's Berkshire Hathaway (NYSE:BRK.B) (NYSE:BRK.A) increased his stakes in Japanese trading houses Mitsubishi Corp. (OTCPK:MSBHF) and Mitsui Corp. (OTCPK:MITSY) (OTCPK:MITSF), the Japanese companies said, according to a media report.

The insurance and investing firm boosted its stake in Mitsubishi to 10.23% from 9.74% as of Aug. 28, 2025, Mitsubishi said in a filing.

Separately, Berkshire Hathaway (NYSE:BRK.B) also increased its holdings in Mitsui (OTCPK:MITSY), but didn't disclose the amount, as its holdings remain below 10% of the company's outstanding stock, Bloomberg reported, citing a statement from a Mitsui spokesperson. The Omaha, Nebraska-based company held 9.82% of Mitsui as of March, according to data compiled by Bloomberg.

Berkshire Hathaway (NYSE:BRK.B) also has holdings in Marubeni Corp. (OTCPK:MARUY) (OTCPK:MARUF), Itochu Corp. (OTCPK:ITOCF) (OTCPK:ITOCY), and Sumitomo Corp.(OTCPK:SSUMY) (OTCPK:SSUMF).

The U.S. conglomerate started buying shares in the sprawling Japanese companies about six years ago. Initially, Berkshire (NYSE:BRK.B) agreed to keep its holdings of each of the five Japanese companies below 10%, but "as we approached this limit, the five companies agreed to moderately relax the ceiling," Buffett said in his annual letter to Berkshire stockholders in February. "Over time, you will likely see Berkshire's ownership of all five increase somewhat."