Up to 300 jobs are to be cut at carmakers Jaguar and Land Rover in the West Midlands and Merseyside.
Bosses at the Ford-owned companies are asking for voluntary redundancies among office workers.
The four affected sites are Castle Bromwich in Birmingham, Gaydon in Warwickshire, Whitley in Coventry and Halewood on Merseyside.
Jaguar and Land Rover spokesman Don Hume said it was part of a business restructuring process.
He said: "We have a voluntary redundancy programme in place for up to 300 salaried staff right across the Jaguar/Land Rover organisation in Britain.
"It's part of ongoing business restructuring and in line with what the parent company Ford is doing on a global scale."
A spokesman for the Transport and General Workers' Union said: "We have been advised there are a limited number of people who will be allowed to leave the company voluntarily."