On Friday, the UAW said it would strike at GM's Lansing Delta Township assembly plant that makes the Buick Enclave and Chevrolet Traverse SUVs after previously striking at GM's Missouri assembly plant and 18 parts distribution centers.

Last month, GM said it had idled its Fairfax, Kansas plant because of a parts shortage stemming from the strike, resulting in 2,000 indefinite layoffs. Ford said last month it temporarily laid off about 600 workers at a Michigan auto plant because of the strike. Stellantis has furloughed nearly 370 workers in Ohio and Indiana

The new GM furloughs include 130 at its Parma, Ohio Metal Center and 34 at its Marion, Indiana Metal Center.

On Friday, UAW President Shawn Fain expanded the first-ever simultaneous strike against the Detroit Three to a GM Lansing plant and Ford Motor Chicago assembly plant, but Stellantis was spared after last-minute concessions by the Chrysler parent.

The UAW was holding new bargaining sessions with GM and Stellantis on Monday, and the union also said it reached a new labor agreement Volvo Group-owned Mack Trucks covering 4,000 workers just before the Sunday night deadline.

The tentative agreement that includes significantly increased wages must still be ratified, the union said.

JPMorgan said in a research note Monday it estimated the strike has cost GM $191 million and Ford $145 million but said there was some cause for optimism about a deal "including that the two sides being reportedly close on pay and benefits."

On Friday, the chief executives of GM and Ford blasted the UAW, hours after the union escalated the strike. The UAW responded on social media that neither CEO had attended bargaining talks.

Anderson Economic Group estimated total losses from the first two weeks of the strike at $3.9 billion, including $325 million in wages, $1.12 billion in losses for the Detroit Three, $1.29 billion for suppliers and $1.2 billion for dealer and customer losses.