The company's operating profit was 268.9 billion yen ($2.54 billion) in the first quarter, versus an average estimate of 268 billion yen from four analysts polled by Refinitiv.

Its smartphone subscribers rose 372,000 from three months earlier as SoftBank markets a plan targeting heavy data users.

The telco maintained its full-year operating profit forecast at 890 billion yen, up 9% from the previous year.

SoftBank Corp has hiked its stake in Yahoo Japan Corp  and turned the internet company into a subsidiary to drive growth outside its wireless business.

The Yahoo stake and its first ever share buyback announced last month have helped support SoftBank Corp's shares, which debuted, and have languished, below their 1,500 yen IPO price.

The stock closed down 0.5% ahead of the earnings. SoftBank Corp had Japan's largest ever listing in December as parent SoftBank Group Corp refocuses on technology investing.

The telco's outline for expansion includes a platform for autonomous driving that it has set up with Toyota Motor and plans to export.

Such ventures will require the high-speed, low-latency 5G  services set to begin in Japan next year and that Chief Executive Ken Miyauchi says will drive growth at the telco and calm fears that the country's market has hit maturity.