NEW YORK (AP) — CBS News said Friday it is shutting down its storied radio news service after nearly 100 years of operation as part of a round of layoffs, blaming a shift in radio station programming strategies and challenging economic times.

When it went on the air in September 1927, CBS News Radio was the precursor to the entire network, giving a youthful William S. Paley a start in the business. Famed broadcaster Edward R. Murrow delivered reports from London during World War II as part of the service.

Today CBS News Radio provides material to an estimated 700 stations across the country, and is known best for its top-of-the-hour news roundups. The service will end on May 22, the network said Friday.

“While this was a necessary decision, it was not an easy one,” CBS News editor-in-chief Bari Weiss and president Tom Cibrowski said in a memo to staff on Friday.

David Bauder, The Associated Press