Microsoft Corp. will begin to reduce the size of its overall workforce by up to 18,000 jobs in the next year, according to a memo Microsoft CEO Satya Nadella sent to employees this morning. Nokia Devices and Services is expected to account for about 12,500 jobs, comprising both professional and factory workers.

The changes will affect both the Microsoft workforce and the company’s vendor staff.

“We are moving now to start reducing the first 13,000 positions, and the vast majority of employees whose jobs will be eliminated will be notified over the next six months,” Nadella wrote.

Read the entire memo here.