Mizuho Financial Group Inc. shut down its automated teller machine network and online banking service for the weekend to address computer problems that have plagued the company since March 15.
During a press conference Friday, executives at Mizuho, Japan's third-largest bank, said it planned to reboot the affected systems by March 21, though it might take an extra day to fully restore the system.
The bank has 5,622 ATMs in its network.
Mizuho announced some 620,000 salary-payment transactions worth $1.5 billion were not processed on Friday because of the computer problem, which was yet to be identified. The bank advised its customers whose pay was affected by the problem to visit any of its 440 branches, where they may withdraw up to 100,000 yen.
The bank's president, Satoru Nishibori, told reporters Mizuho is still investigating the branches where the problems started.
Mizuho expected the ATM problem to affect about 1 million customers, who also were unable to conduct transactions at another bank's ATMs because of the problems.
Nishibori suggested on Thursday that a surge in financial transactions in the aftermath of last week's earthquake and tsunami might be causing the computer issues. A bank representative told The Wall Street Journal Mizuho does not believe the natural disasters caused the problems.
Nicole Sturgill, a research director in the retail banking and cards practice at TowerGroup, said the issues likely stem from a systems problem. "I would first look at their [information technology] locations to see if that might be the root issue," she said.
