TOKYO: Branches of the main banking unit of Mizuho Financial Group were unable to process transactions on Friday (Aug 20), the latest in a series of system errors.
The glitch prevented in-person transactions at Mizuho's bank branches nationwide, a spokesperson said, adding that its automated teller machines (ATMs) and online banking services were unaffected by the outage.
Service had been restored with some exceptions by 9.50am local time (8.50am, Singapore time), Mizuho said on its website. It was unclear how big a financial impact it would have Japan's third-largest lender.
From a reputational standpoint, however, it is likely to fuel further concern about the bank, which suffered four system breakdowns between February and March this year, despite having spent more than US$3.6 billion to overhaul its systems in 2019.
That revamp followed two large-scale breakdowns in 2002 and 2011.
The Mizuho spokesperson said the glitch had also affected the group's trust bank unit and the cause of the latest problem appeared to be different to the previous ones.
The Nikkei business daily reported the bank's backup system failed to operate, paralysing money transfers in and outside Japan.
Japanese chief cabinet secretary Katsunobu Kato said at a regular press conference that the system glitch was regrettable and that regulators must respond firmly.
A report in June commissioned by the bank found that its corporate culture - including an atmosphere where managers are reluctant to express their opinions and unable to respond well to crises - was to blame for its tech problems.