TOKYO -- Japan's Sumitomo Mitsui Financial Group is in final talks to acquire about a 10% stake in SBI Holdings with the aim of boosting their securities businesses, Nikkei has learned, in a deal that could be worth more than 60 billion yen ($440 million).

SMFG, as a traditional megabank group, has a solid corporate customer base in Japan, while relatively new SBI has plenty of young retail customers. Combining their strengths, the two companies are seeking to deepen penetration in the domestic market.

SBI is expected to issue new shares to SMFG, according to sources, subject to regulatory approval by U.S. authorities. SBI is also likely to consider a small investment in SMFG.

SBI Securities, a unit of SBI Holdings, is Japan's largest online securities company with a strong retail customer base. It had over 6 million accounts as of the end of March 2021 but has yet to penetrate the corporate and wealthy individuals segments of the market. Its assets under management amount to about 19 trillion yen, lower than those of major securities companies.

SBI has been forming alliances with Japanese regional banks as part of its drive to become the fourth megabank, after Sumitomo Mitsui, Mitsubishi UFJ and Mizuho. To this end, it took over Shinsei Bank in 2021, but that acquisition added to its burden of interest payments. As such, strengthening its financials by raising new capital has become a key challenge for SBI.