A photo illustration shows the Microsoft logo displayed on a Nokia phone in Vienna in this file photo taken September 3, 2013.  [Photo/Agencies]

US software giant Microsoft Corp is to cut around 90 percent of its workforce at a handset development site in Beijing, according to an internal document acquired by China Daily on Saturday.

Only about 300 staff at the site, purchased from Nokia, will keep their jobs, the document shows. There are currently around 3,000 employees. Most are engineers on a low-end handset product line.

"Microsoft will outsource the higher-end devices after the layoffs," said a person familiar with the job cuts speaking on condition of anonymity.

Microsoft CEO Satya Nadella announced the biggest downsizing in company history in mid-July, cutting 18,000 jobs worldwide.

The biggest layoffs will come from the Nokia unit as the company shifts its emphasis to cloud business.