The falloff has led to projections of an annual operating deficit and internal discussions about staff and program cuts.

Another problem area: The strong audience growth that NPR’s news and entertainment programs experienced over the past decade appears to have flattened, a potentially worrisome development because more stations are carrying NPR’s programs…

NPR has operated at a deficit in three of the past four years, Knell said in an interview Wednesday, and it has had to dip into its endowment to cover its expenses in those years.

But the hole is growing deeper: Through March, NPR recorded a $2.6 million deficit, over and above what its endowment covers. The growing deficit makes it “likely” that NPR will end its fiscal year in September in the red, said Dana Davis Rehm, a spokeswoman.