By Dave Sebastian

General Motors Co. has agreed to recall 5.9 million SUV and pickup-truck models to replace potentially faulty Takata air-bag inflaters, a fix that could cost the auto maker more than $1 billion.

GM had asked the National Highway Traffic Safety Administration not to order a recall of the vehicles because the auto maker believed they were safe. The agency denied that request Monday, saying its research shows Takata inflaters installed in GM vehicles are prone to the deadly explosions reported in other auto makers' cars.

The vehicles GM has agreed to recall include some of its bestselling models from the 2007 to 2014 model years, including Chevrolet Silverado and GMC Sierra pickups, Cadillac Escalade SUVs, Chevy Tahoe and Suburban SUVs and GMC Yukon SUVs.

The Takata air-bag recall has been one of the largest and most complex in U.S. history, involving 19 auto makers and tens of millions of vehicles, according to the NHTSA.

The agency says a design defect can cause the air-bag inflaters to degrade over time, putting them at risk of exploding during a crash and sending shrapnel-like metal fragments into the cabin.

Joyson Safety Systems, which acquired Takata's assets after the air-bag maker filed for bankruptcy in 2017, didn't immediately respond to a request for comment.

Incidents involving ruptured Takata air bags have killed 18 people in the U.S. and at least 12 more elsewhere, the NHTSA said. GM has previously recalled some models for faulty Takata inflaters, but it had petitioned the NHTSA four times since 2016 to avoid this latest one.

The auto giant said evidence from independent evaluation shows inflaters don't need to be replaced. It has said that it is aware of nearly 67,000 air-bag deployments without a single rupture involving the models the NHTSA identified and that the vehicle and inflater design differs from that of other affected cars, making the models safe.

The NHTSA said in its decision that GM's claim that the vehicles aren't at risk is unfounded.

GM, which has said in previous federal filings that replacing the inflaters would cost about $1.2 billion, said Monday that it would begin the process of fixing them.

"We disagree with NHTSA's position. However, we will abide by NHTSA's decision and begin taking the necessary steps," GM said.

The auto maker's shares were up 2.8% in midday trading.

The NHTSA said it had conducted engineering and field tests that show "the GM inflators in question are at risk of the same type of explosion after long-term exposure to high heat and humidity as other recalled Takata inflators."

The agency gave GM 30 days to submit a schedule for notifying vehicle owners and beginning the process of replacing the parts in question.

--Mike Colias contributed to this article.

Write to Dave Sebastian at dave.sebastian@wsj.com

Corrections & Amplifications

This article was corrected at 4:47 p.m. ET because the original version incorrectly gave the name of Takata as Tataka in two instances.

(END) Dow Jones Newswires

11-23-20 1301ET