Major American airlines are grounded, stranding travelers amid a widespread Microsoft outage that is disrupting flights, banks, press organizations, and companies around the world on Friday.

The Federal Aviation Administration says the airlines United, American, Delta, and Allegiant had all been grounded. Travelers at Los Angeles International Airport slept on a jetway floor, using backpacks and other luggage for pillows, due to a delayed United flight to Dulles International Airport early on Friday.

Escalating disruptions continued hours after the technology company said it was gradually fixing an issue affecting access to Microsoft 365 apps and services.

The website DownDectector, which tracks user-reported internet outages, recorded growing outages in services at Visa, ADT security, and Amazon, and airlines including American Airlines and Delta.

News organizations in Australia reported that airlines, telecommunications providers, and banks, and media broadcasters were disrupted as they lost access to computer systems. Airlines in the United Kingdom, Europe, and India reported problems and some New Zealand banks said they were offline.

Microsoft 365 posted on X that the company was “working on rerouting the impacted traffic to alternate systems to alleviate impact in a more expedient fashion” and that they were “observing a positive trend in service availability.”

The company did not respond to a request for comment. It did not explain the cause of the outage further.

New Zealand’s acting prime minister, David Seymour, said on X that officials in the country were “moving at pace to understand the potential impacts” of the global problem.

“I have not currently received any reporting to indicate these issues are related to malicious cyber security activity,” Mr. Seymour wrote. The issue was causing “inconvenience” for the public and businesses, he added.

Israel’s Cyber Directorate that it was among the places affected by the global outages, attributing them to a problem with the cybersecurity platform Crowdstrike. 

The outage also hit the country’s post offices and hospitals, according to the ministries of communication and health.

Meanwhile, major disruptions reported by airlines and airports grew.

Airlines, railways and television stations in the United Kingdom were being disrupted by the computer issues. The budget airline Ryanair, train operators TransPennine Express and Govia Thameslink Railway, as well as broadcaster Sky News are among those affected.

“We’re currently experiencing disruption across the network due to a global third party IT outage which is out of our control,’’ Ryanair said. “We advise all passengers to arrive at the airport at least three hours before their scheduled departure time.”

Edinburgh Airport said the system outage meant waiting times were longer than usual. London’s Stansted Airport said some airline check-in services were being completed manually, but flights were still operating.

Widespread problems were reported at Australian airports, where lines grew and some passengers were stranded as online check-in services and self-service booths were disabled. 

Passengers in Melbourne queued for more than an hour to check in, although flights were still operating.

Airline operations in India were disrupted, affecting thousands.

The privately-owned IndiGo airlines told the passengers on X that the Microsoft outage on Friday impacted airline operations in India, inconveniencing thousands of passengers.

Several airlines made statements on X saying that they were following manual check-in and boarding processes and warned of delays due to technical problems.

Hong Kong’s Airport Authority said in a statement that the outage was affecting some airlines at the city’s airport and they had switched to manual check-in.

Amsterdam’s Schiphol Airport said on its website that the outage was having a “major impact on flights” to and from the busy European hub. The outage came on one of the busiest days of the year for the airport, at the start of many people’s summer vacations.

In Germany, Berlin Airport said Friday morning that “due to a technical fault, there will be delays in check-in.” It said that flights were suspended until 10 a.m. without giving details, German news agency dpa reported.

Zurich Airport, the busiest in Switzerland, suspended landings on Friday morning but said flights headed there that were already in the air were still allowed to land. 

It said that several airlines, handling agents and other companies at the airport were affected, and that check-in had to be done manually in some cases, but that the airport’s own systems were running.

At Rome’s Leonardo da Vinci airport, some American-bound flights had posted delays, while others were unaffected.

Australia appeared to be severely affected by the issue. Outages reported on the site DownDetector included the banks NAB, Commonwealth and Bendigo, and the airlines Virgin Australia and Qantas, as well as internet and phone providers such as Telstra.

Hospitals in Britain and Germany also reported problems.

Several practices within the National Health Service in England reported that the outage had hit their clinical computer system that contains medical records and is used for scheduling.

“We have no access to patient clinical records so are unable to book appointments or provide information,” Church Lane Surgery in Brighouse in Northern England said on the social media platform X. “This is a national problem and is being worked on as a high priority.”

The NHS did not immediately respond to requests for comment.

In northern Germany, the Schleswig-Holstein University Hospital, which has branches in Kiel and Lübeck, said it had canceled all elective surgery scheduled for Friday, but patient and emergency care were unaffected.

News outlets in Australia — including the ABC and Sky News — were unable to broadcast on their TV and radio channels, and reported sudden shutdowns of Windows-based computers. Some news anchors broadcast live online from dark offices, in front of computers showing “blue screens of death.”

In South Africa, at least one major bank said it was experiencing “nationwide service disruptions” as customers reported they were unable to make payments using their bank cards at grocery stores and gas stations.

The New Zealand banks ASB and Kiwibank said their services were down.

An X user posted a screenshot of an alert from the company Crowdstrike that said the company was aware of “reports of crashes on Windows hosts” related to its Falcon Sensor platform. 

The alert was posted on a password-protected Crowdstrike site and could not be verified. Crowdstrike did not respond to a request for comment.