CBS News has said it is shutting down its radio service after nearly 100 years in May, in a fresh round of layoffs.

The service is expected to end on 22 May, affecting more than 700 affiliate stations, the editor-in-chief, Bari Weiss, and president Tom Cibrowski announced on Friday.

Employees will be notified by the end of the day if their job has been affected, they said. The cuts could impact about 6% of its workforce, or more than 60 people, US media report.

"While this was a necessary decision, it was not an easy one," Weiss and Cibrowski said, adding that a "shift in radio station programming strategies" and economic challenges "made it impossible to continue the service".

"...Parts of our newsroom must get smaller to make room for the things we must build to remain competitive," they said.