Most of the jobs -- about 2,000 -- would come from the company's mobile phone division, Crain's Chicago Business reported Thursday.
Motorola's mobile phone sales slid 9 percent in the third quarter, dropping the company to fourth in phone sales behind Sony Ericsson, Samsung Electronics and Nokia Oyj, Crain's reported. Just a year ago, the company was ranked second in mobile phone sales, Crain's said.
Motorola, which lost $397 million in the third quarter, also said it would postpone its planned breakup, offering no date for when the company would split into two.
The previously announced target date for spinning off the company's cellphone division from its other electronic products was October.
"While we will continue to prioritize investments on opportunities for growth, we are also improving our cost structure across the company," Brown said in a statement.