Microsoft will soon announce a massive round of layoffs, according to a new report from Bloomberg. Thousands of employees will be let go as Microsoft looks to integrate the devices and services business it recently acquired from Nokia. The report says that the reductions could be announced as soon as this week, and it could be Microsoft’s biggest ever round of layoffs, topping the 5,800 cuts it made five years ago in 2009.

Bloomberg says that while the majority of the job cuts will impact new employees that came over from Nokia following the recent handset division acquisition, other areas of Microsoft will be impacted as well. Specifically, the report says “divisions of Microsoft that overlap” with Nokia’s devices business will see cuts, as will Microsoft’s marketing and engineering divisions.

The news of imminent layoffs at Microsoft comes less than a week after new CEO Satya Nadella issued the company’s new manifesto.