The company forecast that with the additional stake in Yahoo, its net profit will rise to 480 billion yen ($4.4 billion) in the current fiscal year, up from 430.8 billion yen in the year that ended in March. Revenue is expected to rise to 4.8 trillion yen ($43.6 billion) from 3.7 billion yen in the last fiscal year.
Softbank, the Japanese mobile subsidiary of Softbank Group Corp., listed its shares in December in Japan's largest-ever initial public offering, at more than 2 trillion yen ($18 billion).
It how holds a 12% stake in Yahoo Japan, which will become a subsidiary of Softbank Corp. with its acquisition of a 36% stake in the internet company held by its parent.
Softbank Group is due to announce its latest earnings on Thursday.
Softbank Corp. said it expects that cooperating with Yahoo Japan and tapping its big data base will help it expand its consumer and business services and tailor them to better suit the needs of its customers.
Softbank's founder Masayoshi Son has said he aims to prepare the company to grow continuously for 300 years based on a strategy of investing as a strategic holding company across a spectrum of industries that are leading the "Information Revolution."