Masayoshi Son is stepping down as chairman of SoftBank Corp., completing a transition of leadership at the domestic telecommunication unit that had been at the center of his technology empire.

Ken Miyauchi, who has been chief executive officer, will move into the chairman’s role in Son’s place, while Junichi Miyakawa takes over as CEO, the company said in a statement. Son spun the wireless business out of his SoftBank Group Corp. in 2018 and has sold his stake down to about 40%, according to data compiled by Bloomberg.

Telecom services had long been the cornerstone of Son’s conglomerate, but he has been shifting his attention to financial investments. His $100 billion Vision Fund has taken stakes in scores of startups, with many going public in the surging stock market.

Miyauchi joined SoftBank in 1984, just three years after it was created. One of Son’s longest-serving lieutenants, he helped the founder grow the business from a distributor of personal computer software into a telecommunications conglomerate.

Miyauchi, 71, took charge of the domestic operations when the unit went public and helped engineer the merger of SoftBank’s Yahoo Japan internet business with messaging giant Line Corp.

Miyakawa joined the SoftBank group in 2003 and has since served in a number of technical positions at its broadband operation, the Japan wireless operation and Sprint Corp. The 55-year-old most recently held the role of chief technology officer at SoftBank Corp.

SoftBank Corp. shares have gained about 4% this year and closed little changed Tuesday.