Reports indicate that Ericsson is winding down its R&D facility at Ansty Park in Coventry and will close with the potential loss of 700 jobs by the middle of next year.
According to Unite national officer, Peter Skyte: “This has come as a bolt out of the blue for the workforce and their families who were looking forward to a promising future in this newly opened site"
The company said that the announcement was part of its "ongoing global cost reduction activities and is subject to consultations with trade unions and employee forums."
The site was created following Ericsson's acquisition in 2007 of the former Marconi R&D activities at New Century Park Coventry.
It acquired two research activities from Marconi, advanced telecoms research and optical research.
The site at Ansty was a Greenfield site and came into full operation earlier this year.
In January, the company started a SK 10bn (£880m) cost reduction programme split equally between cost of sales and operating expenses.
"The transition to IP technologies with fewer software platforms as well as products with less hardware paves the way for synergies within the product portfolio. The programme is ahead of plan and additional opportunities for efficiency improvements have evolved during the programme," said Ericsson at the time of its Q3 results.