IBM faced the wrath of the boss of Air New Zealand after the airline was left with over 10,000 stranded and delayed passengers after its systems crashed because routine data center maintenance went wrong.

The airline said that online systems, check in systems and call center systems all failed between 9am and 3:30pm on Sunday.

Following this reports cited Air New Zealand CEO Rob Fyfe as fuming at IBM in an internal email.

"In my 30-year working career, I am struggling to recall a time where I have seen a supplier so slow to react to a catastrophic system failure such as this and so unwilling to accept responsibility and apologise to its client and its client's customers," he says.

IBM issued a statement saying: "At 9.03am on Sunday morning during a scheduled maintenance check at IBM's Newton Data Centre, the back up generator experienced a power failure, which caused a disruption to its clients.

"One client's system in particular was badly affected on Sunday, but IBM's technical support team has now reinstated all client services."