Ericsson has announced 950 job cuts on top of those already announced as part of its cost-cutting plan.
The jobs will be cut in Sweden and add to cuts planned to save £1.4bn, which includes the loss of 700 UK jobs at a research and development centre in Coventry.
The work at Ansty Park, near Coventry is being moved offshore to China.
Peter Skyte, Unite national officer for IT and communications, said this will lead to a loss of highly skilled work that is central to future strategic technological development in the UK. "The country's capacity to compete for future R&D work will be diminished."