Online financial group SBI Holdings Inc. said Saturday it has succeeded in its tender offer for Shinsei Bank, raising its stake in the midsize lender to 47.77% from the current roughly 20% for ¥113.8 billion ($1 billion).

The announcement capped off a three-month bid that at one point turned hostile, a rare development in the Japanese financial sector. SBI launched the takeover bid in September, offering ¥2,000 per share and setting the bid's upper limit at 48%.

The tender offer ended Friday.

SBI, which also operates real estate and pharmaceutical businesses, now plans to apply for approval to set up a bank holding company by the end of the year at the earliest to take a majority stake in Shinsei through additional share purchases.

SBI has formed alliances with regional banks, aiming to become the fourth Japanese megabank.

Shinsei once objected to SBI's offer and sought approval to introduce defensive measures at an extraordinary shareholders' meeting. But the bank gave up the plan last month as it looked increasingly difficult without support from the central government, one of its major shareholders.

The government injected ¥370 billion in public funds after the bank's predecessor, the Long-Term Credit Bank of Japan, collapsed in 1998 in the wake of the bursting of the country's economic bubble. About ¥350 billion has yet to be repaid.