Berkshire Hathaway plans to increase its stake in Japan’s five largest trading houses after securing an agreement to ease its previous 10% ownership cap, chairman Warren Buffett said in an annual letter to shareholders. The conglomerate, which has held stakes in Mitsubishi Corp, Mitsui & Co, Itochu Corp, Sumitomo Corp, and Marubeni Corp, intends to hold its Japanese investments for “many decades” and explore further collaboration. The trading houses’ stocks have benefited long-term from Buffett’s backing but have faced recent market pressures. Berkshire, which saw operating earnings surge 71% in Q4 to USD14.5bn, continues to generate strong returns from insurance and investment income. Mitsubishi Corp confirmed discussions with Berkshire on potential joint projects and long-term value creation.