Systems vendor IBM has admitted that an error by one if its maintenance staff took down the IT infrastructure of a Singapore bank for seven hours, disrupting its ATMs and online banking services.

DBS Bank, one of Asia’s largest financial institutions, released a statement saying it took “full responsibility” for the downtime while simultaneously blaming IBM. It explained that while the computing giant’s staff were making routine repairs to a disk storage system at 3am “a procedural error inadvertently triggered a malfunction in the multiple layers of systems redundancies, which led to the outage”.

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“We understand from IBM that an outdated procedure was used to carry out the repair,” said DBS CEO Piyush Gupta. “In short, a procedural error in what was to have been a routine maintenance operation subsequently caused a complete system outage.”

IBM has accepted responsibility for the fault but insisted that no data had been lost during the downtime. “Unfortunately, a failure to apply the correct procedure inadvertently caused the service outage,” it said in a statement.

It add that it will increase efforts to ensure that employees were up to date in correct maintenance procedure.“IBM has also taken steps to enhance training of our personnel related to current procedures and brought in experts from our global team to provide further assistance.”

DBS could now face punishment from the Singapore Monetary Authority, which said earlier in a statement that it was considering appropriate action. The bank signed $868 million IT outsourcing deal with IBM in 2002.