AT&T will postpone new wireless service near some airports planned for this week after the nation’s largest airlines said the service would interfere with aircraft technology and cause massive flight disruptions.

Also read: Microsoft to acquire gaming giants Activision Blizzard in $68.7 billion deal

The company said Tuesday it would delay turning on new cell towers around runways at some airports — it did not say how many — and work with federal regulators to settle a dispute over potential interference from new 5G service.

The decision came after the airline industry raised the stakes in a showdown with AT&T and Verizon over plans to launch new 5G wireless service this week, warning that thousands of flights could be grounded or delayed if the rollout takes place near major airports.

Also read: A year of Joe Biden’s presidency: Lofty ambitions, unfulfilled promises

Verizon and a trade group for the telecom industry, CTIA, did not immediately respond to requests for comment.

On Monday, CEOs of the nation’s largest airlines said that interference from the wireless service will be worse than they originally thought.

“To be blunt, the nation’s commerce will grind to a halt” unless the service is blocked near major airports, the CEOs said in a letter Monday to federal officials including Transportation Secretary Pete Buttigieg, who has previously taken the airlines’ side in the matter.

The airlines asked that the new, faster mobile service be banned within two miles of runways.

AT&T and Verizon planned to activate their new 5G wireless service Wednesday after two previous delays from the original plan for an early December rollout.

Also read: Before pullout, watchdog warned of Afghan air force collapse

The new high-speed 5G service uses a segment of the radio spectrum that is close to that used by altimeters, which are devices that measure the height of aircraft above the ground. Pilots use altimeters to land when visibility is poor, and they link to other systems on planes.

AT&T and Verizon say their equipment will not interfere with aircraft electronics, and that the technology is being safely used in many other countries.

However, the CEOs of 10 passenger and cargo airlines including American, Delta, United and Southwest say that 5G will be more disruptive than they originally thought because dozens of large airports that were to have buffer zones to prevent 5G interference with aircraft will still be subject to flight restrictions announced last week by the Federal Aviation Administration. They add that those restrictions won’t be limited to times when visibility is poor.

“Unless our major hubs are cleared to fly, the vast majority of the traveling and shipping public will essentially be grounded. This means that on a day like yesterday, more than 1,100 flights and 100,000 passengers would be subjected to cancellations, diversions or delays,” the CEOs said.

The airline CEOs asked that the new 5G be barred within two miles of airport runways.

The showdown between two industries and their rival regulators — the FAA and the Federal Communications Commission, which oversees radio spectrum — now threatens to further disrupt the aviation industry, which has been hammered by the pandemic for nearly two years.

This was a crisis that was years in the making.

The airline industry and the FAA say that they have tried to raise alarms about potential interference from 5G C-Band but the FCC has ignored them.

The telecoms, the FCC and their supporters argue that C-Band and aircraft altimeters operate far enough apart on the radio spectrum to avoid interference. They also say that the aviation industry has known about C-Band technology for several years but did nothing to prepare — airlines chose not to upgrade altimeters that might be subject to interference, and the FAA failed to begin surveying equipment on planes until the last few weeks.

After rival T-Mobile got what is called mid-band spectrum from its acquisition of Sprint, AT&T and Verizon spent tens of billions of dollars for C-Band spectrum in a government auction run by the FCC to shore up their own mid-band needs, then spent billions more to build out new networks that they planned to launch in early December.

In response to concern by the airlines, however, they agreed to delay the service until early January.

Late on New Year’s Eve, Buttigieg and FAA Administrator Stephen Dickson asked the companies for another delay, warning of “unacceptable disruption” to air service.

AT&T CEO John Stankey and Verizon CEO Hans Vestberg rejected the request in a letter that had a scolding, even mocking tone. But they had second thoughts after intervention that reached the White House. They agreed to the second, shorter delay but implied that there would be no more compromises.

That was followed by a deal in which the telecoms agreed to reduce the power of their networks near 50 airports for six months, similar to wireless restrictions in France. In exchange, the FAA and the Transportation Department promised not to further oppose the rollout of 5G C-Band.

President Joe Biden praised the deal, but the airlines weren’t satisfied with the agreement, regarding it as a victory for the telecoms that didn’t adequately address their concerns about trying to land planes at airports where the new service would be active.