(Recasts with Telstra restoring services)
SYDNEY, July 11 (Reuters) - Australian banks and retailers were getting back online on Thursday after a nationwide telecoms outage knocked out electronic payment systems and cash machines for several hours.
Telstra TLS.AX , the country's biggest telecoms provider, said service was being restored to a number of large customers but did not give details about the nature of the problem.
Australia's four major banks had said some of their transaction-handling machines in stores were not working early on Thursday afternoon. Retailers and a state ambulance service also reported service disruptions.
"Good news. Many of our services are starting to restore. We'll provide another update when we know more," Telstra said in a post on social media.
Telstra is regarded as Australia's premium communications provider, but has been embarrassed in the past by service outages. In 2016, customers suffered six internet or telecoms outages.
Commonwealth Bank of Australia CBA.AX said some services are back to normal and it thanked customers for their patience.
"Our telecommunication provider continues to work to resolve their incident that is impacting our services," the bank said on Twitter.
Westpac Banking Corporation WBC.AX , National Australia Bank Ltd NAB.AX and Australia and New Zealand Banking Group ANZ.AX had also reported problems with automated teller machines and payment processing.
The New South Wales ambulance service said there have been no interruptions to emergency services while it works with Telstra to resolve technical issues.
The nation's biggest grocer, Woolworths Group Ltd WOW.AX , said cashiers were processing transactions manually.
A Reuters reporter at one supermarket in Sydney said the problem caused havoc as automated checkouts - which account for most checkouts at many stores - were shut down and staff checked customers' signatures to process card payments.