Customers of Japan Post will be able to do their banking at convenience stores under a tieup between the public postal corporation and Sumitomo Mitsui Banking Corp. and IY Bank, sources said Monday.

Customers of Japan Post, which will begin operating in April, will be able to withdraw cash from 1,000 SMBC automatic teller machines beginning in July, and 5,000 IY Bank ATMs beginning in May, they said.

Postal officials were expected to release the plan Tuesday, they said.

Japan Post's planned partnerships with SMBC, a core bank of Sumitomo Mitsui Financial Group Inc., and IY Bank would mark its first full-scale business tieup with private-sector financial institutions.

Although postal savings customers can already withdraw money from bank ATMs, they have never had wide access to round-the-clock services.

Other than a few locations featuring 24-hour trial services, post offices in Japan offer no late-night or early morning ATM access, prompting many people in metropolitan areas to call for such services.

Because operating ATMs full time is expensive, Japan Post has apparently decided to tie up with private-sector financial institutions to enable access to ATMs at convenience stores.

IY Bank operates about 5,000 ATMs at Seven-Eleven Japan Co. stores, and SMBC has ATMs installed at more than 1,000 am/pm Japan Co. stores.

It will cost 210 yen per transaction for postal savings customers to withdraw money through these ATMs, the sources said.

Customers of both banks, which mainly operate in metropolitan areas, will be able to use ATMs at 24,000 post office locations nationwide, they said.

Japan Post will take over mail delivery, postal savings and "kampo" life insurance on April 1.