Australia's central bank, the postal service and several commercial lenders as well as other companies grappled with internet outages on Thursday, disrupting customer accounts and financial transactions before some services were restored late in the day.
The Reserve Bank of Australia said on Thursday it was cancelling its operation to buy long-dated government bonds because of the technical difficulties.
"Due to technical difficulties, today's RBA long-dated open market operations auction has been cancelled," the bank said on its dealing page on Thursday.
Many of the affected websites in Australia, such as those belonging to the Commonwealth Bank of Australia, Westpac Banking Corp and Australia and New Zealand Banking Group, had started to come back online late afternoon on Thursday.
CBA said in a tweet it was starting to see services return to normal following a tech outage that had had widespread impact across its businesses.
Virgin Australia, the country's No. 2 airline, said on Twitter it was experiencing a system outage.
Websites of major US airlines, American Airlines, Southwest Airlines, United Airlines and Delta Air Lines, also experienced disruptions early on Thursday, according to outage monitoring website Downdetector.
It was not immediately clear if the outages in Australia and the United States were linked.
An executive at one of the Australian banks told Reuters the issue had been a problem with its host and service provider. The servers had to be re-routed to fix the issue, said the person who was not authorised to speak to media and declined to be identified.
Representatives at the Australian banks did not immediately respond to requests for comment.


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