The deal between Citigroup and SMBC, cost of which is still unknown, will include the sale of 740,000 accounts worth about $21 billion. Reuters

Citigroup will sell its retail-banking unit in Japan to Sumitomo Mitsui Banking Corp. (SMBC), a Japanese multinational banking and financial services company headquartered in Chiyoda, Tokyo, the companies announced Thursday.

SMBC Trust Bank Ltd., a wholly-owned subsidiary of SMBC, will acquire the retail-banking business of Citibank Japan, which includes about 2.5 trillion yen (about $21 billion) deposited in nearly 740,000 customer accounts. The deal also involves the sale of Citibank Japan's ATMs and 32 retail branches with about 1,600 employees, SMBC said on its website. According to the companies, the transaction is subject to regulatory approvals and is expected to close in October next year.

The cost of the acquisition was not disclosed but, according to a source cited by Bloomberg, SMBC is expected to pay about 40 billion yen (about $333 million) to acquire Citigroup’s Japanese retail-banking unit. The announcement of the acquisition comes at a time when SMBC is trying to generate more profits by serving wealthy clients in Japan, which has about $14 trillion in household financial assets, Bloomberg reported.

In addition, Citigroup reportedly said that it is also considering selling its credit card business in Japan, as part of a broader effort to streamline its global banking business that will have an increased focus on corporate and investment banking, The Associated Press reported.

On Wednesday, Citigroup stock closed 2.46 percent up at $54.54 in New York. Sumitomo Mitsui Financial Group, Inc. stock closed up 1.08 percent in Tokyo markets on Thursday.