Skype’s main London office is to be closed by Microsoft, according to the Financial Times.
Up to 220 of the 400 people employed on Skype and Yammer in the capital are at risk of being made redundant.
The site was the primary engineering base for Skype, founded in London in 2003, prior to its purchase by Microsoft for £6.5 billion in 2011.
In a statement to the Financial Times, Microsoft said it will “unify some engineering positions” in London and move workers to a new site in Paddington.
However it said that it will be “entering into a consultation process to help those affected by the redundancies”.
It added: “Microsoft will… offer new opportunities, where possible.
“We are deeply committed to doing everything we can to help those impacted through this process.”
Microsoft said in July that it would be laying off 2,850 workers in the final quarter of this year.
Sources told the FT that the London operation has been reduced in importance over time, with a number of executives leaving over the last few years.
Microsoft has also worked on Skype from its United States base as it integrates features into Office 365.
It is thought that Skype will now be built exclusively from Redmond, Washington state.