Berkshire Hathaway said it raised its holdings in five major Japanese trading houses, just weeks after Warren Buffett said the company’s stakes in them would likely increase somewhat over time.

National Indemnity, a wholly owned unit of Berkshire Hathaway, said in regulatory filings on Monday that it increased its stakes in the five trading houses by between 1.0% and 1.7%. It now holds a stake of between 8.5% and 9.8% in the five companies: Itochu Corp., Sumitomo Corp., Marubeni Corp., Mitsubishi Corp. and Mitsui & Co.