(In paragraph 6 corrects timing of Crowdstrike alert to Friday)

(Reuters) – A global tech outage was disrupting operations in multiple industries on Friday, with airlines halting flights, some broadcasters off-air and everything from banking to healthcare hit by system problems.

American Airlines, Delta Airlines, United Airlines and Allegiant Air grounded flights citing communication problems. The order came shortly after Microsoft said it resolved its cloud services outage that impacted several low-cost carriers, though it was not immediately clear whether those were related.

“A third party software outage is impacting computer systems worldwide, including at United. While we work to restore those systems, we are holding all aircraft at their departure airports,” United said in a statement. “Flights already airborne are continuing to their destinations.”

Australia’s government said outages suffered by media, banks and telecoms companies there appeared to be linked to an issue at global cybersecurity firm Crowdstrike.

According to an alert sent by Crowdstrike to its clients and reviewed by Reuters, the company’s “Falcon Sensor” software is causing Microsoft Windows to crash and display a blue screen, known informally as the “Blue Screen of Death”.

The alert, which was sent at 0530 GMT on Friday, also shared a manual workaround to rectify the issue.

A Crowdstrike spokesperson did not respond to emails or calls requesting comment.

There was no information to suggest the outage was a cyber security incident, the office of Australia’s National Cyber Security Coordinator Michelle McGuinness said in a post on X.

The outages rippled far and wide.

The travel industry was among the hardest hit with airports around the world, including Tokyo, Amsterdam, Berlin and several Spanish airports reporting problems with their systems and delays.

International airlines, including Ryanair, Europe’s largest airline by passenger numbers, warned of problems with their booking systems and other disruptions.

In Britain, booking systems used by doctors were offline, multiple reports from medical officials on X said, while Sky News, one of the country’s major news broadcasters was off air, apologising for being unable to transmit live.

Banks and other financial institutions from Australia to India and South Africa warned clients about disruptions to their services, while LSEG Group reported an outage of its data and news platform Workspace.

Amazon’s AWS cloud service provider said in a statement that it was “investigating reports of connectivity issues to Windows EC2 instances and Workspaces within AWS.”

It was not immediately clear whether all reported outages were linked to Crowdstrike problems or there were other issues at play. (This story has been corrected to reflect the change in the timing of the Crowdstrike alert to Friday, in paragraph 6)

(Reporting by Reuters bureaus; Writing by Tomasz Janowski; Editing by Emelia Sithole-Matarise)

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