The offering size in the initial public offering of SBI Shinsei Bank could exceed 360 billion yen ($2.39 billion), including overallotment, with Norinchukin planning to buy shares, according to two sources familiar with the matter.

The IPO of SBI Shinsei Bank, a unit of SBI Holdings

, will include the sale of new and existing shares and is due to launch as soon as today, the sources said.

Reuters is reporting the potential size of the offering and Norinchukin’s plan to buy shares for the first time.

Norinchukin, which aims to collaborate with SBI Shinsei Bank, is looking at buying shares worth up to some 5 billion yen, the sources said.