Bank of Tokyo-Mitsubishi and UFJ Bank will suspend operations at their 9,000 automated teller machines nationwide from Saturday night until Monday morning.
The move represents the first in a series of five dry runs aimed at ensuring the safety of the banks' integrated computer systems ahead of their merger Jan. 1.
They will suspend all services between 9 p.m. Saturday and 7 a.m. Monday, including those via ATMs located at convenience stores and Internet banking. Customers will not be able to use their ATM cards at other financial institutions, including post offices, during the period.
The two banks decided to delay their merger by three months to Jan. 1 after the Financial Services Agency expressed concern about the quality of their system integration work.