TOKYO — Billionaire investor Warren Buffett has high hopes for Japan’s well-connected trading houses in an increasingly information-driven world, though the businesses still have much to prove on the ability to turn investments into a driver for growth.

Buffett is in Japan this week and is meeting with the leaders of the five top players — Itochu, Mitsubishi Corp., Mitsui & Co., Sumitomo Corp. and Marubeni. He told Nikkei his Berkshire Hathaway has increased its stake in each of them to 7.4%.