The technology and telecoms conglomerate did not release a forecast for the current business year, saying there were too many uncertain factors.
SoftBank Corp CEO Ken Miyauchi said new services and the adoption of high-speed 5G networks meant the smartphone market had ample room for growth.
The results cover a turbulent three months at Japan’s third-largest mobile phone network provider.
KDDI’s possible investment in Kabu.com Securities, a subsidiary of MUFG, would give it just under a 50% stake.
The moves come as Line seeks alternative revenue streams to offset stagnating user numbers for its app, expanding into areas such as payments, stock broking, insurance and cryptocurrencies.
Saudi Arabia is the largest investor in SoftBank’s $93 billion Vision Fund, giving Son firepower to make big bets in late-stage startups.
It is the latest high-profile hire by SoftBank when it faces criticism for its links to S Arabia, the largest investor in its Vision Fund.
The company last year raised more than $93 billion for its Vision Fund, of which $45 billion came from Saudi Arabia.
It may also be considering an investment of around 20 percent in Don Quijote.
SoftBank Vision Fund’s largest investments to date are in companies including Uber and WeWork.