Long before activist investors swooped into Japan to shake up conglomerates saddled with losses and legacy assets, Hitachi Ltd. managed to do it on its own, selling off more than ¥2 trillion ($18 billion) worth of businesses in the past five years under Chief Executive Officer Toshiaki Higashihara.

The result? A market value that’s more than doubled to ¥6.2 trillion ($54 billion), second only to Sony Group Corp. among Japanese electronics makers and roughly equal to the next two competitors — Panasonic Corp. and Mitsubishi Electric Corp. — combined.

"Activists have never said anything to us,” Higashihara, 66, said in an interview at Hitachi’s headquarters facing Tokyo Station. Since taking over in 2016, the rail-systems engineer is credited with transforming a sprawling conglomerate, once the country’s biggest loss-maker, into a profitable enterprise without the kind of outside intervention from activist funds such as Elliott Investment Management that forced change at Toshiba Corp. and other companies in Japan.