Billionaire Warren Buffett’s stamp of approval is helping Japan’s Mitsubishi shed investor wariness about its complex global business that covers everything from sausages to natural gas. The country’s largest trading house, which operates in 90 countries and regions, has seen heightened interest from potential investors since Buffett’s Berkshire Hathaway (BRKa.N) took a stake in 2020, which later increased. Mitsubishi’s shares have more than tripled, factoring in dividends, while the Nikkei index has climbed 29%. A top executive at the conglomerate