RALEIGH — The head of a Raleigh-based hospital system is telling employees not to worry about a federal investigation of Medicare billing practices despite a federal judge urging prosecutions.

WakeMed CEO Bill Atkinson emailed employees saying a settlement remains active. The hospital system wants to settle the case alleging it over-billed the government for overnight stays though patients were treated and released the same day.

Federal Judge Terrence Boyle on Thursday refused to sign a proposed deferred prosecution agreement he called little more than a "slap on the hand" for a "too big to fail" corporate giant.

Boyle told federal prosecutors they should return to him next month with indictments.

WakeMed officials say no one was fired or disciplined because of the investigation.