General Motors (GM) and Ford said they would be laying off a further 500 workers at four mid western plants due to the impact of the United Auto Workers (UAW) strike, Reuters reported.

Ford said it was furloughing 330 workers at its Chicago stamping and Lima, Ohio engine plants, while GM layoffs included 130 at its Parma, Ohio metal centre and 34 at its Marion, Indiana metal centre.

Lat Friday the UAW struck GM’s Lansing Delta Township assembly plant, which makes the Buick Enclave and Chevrolet Traverse SUVs, after previously striking at the Missouri assembly plant and 18 parts distribution centres, the news agency said.

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 last month temporarily laid off 600 workers at a Michigan auto plant.

Stellantis has furloughed 370 workers in Ohio and Indiana.

JPMorgan in a research note cited by the news agency estimated the strike had cost GM US$191m and Ford US$145m but said there was some cause for optimism about a deal, citing reports that the two sides were “close on pay and benefits”.

The UAW said it presented a new contract offer to GM on Monday.

GM said it received the counterproposal “but significant gaps remain”, the report added.