The nation's largest distributor of endoscopes and related equipment will pay $646 million to resolve separate criminal and civil investigations into kickbacks and foreign bribery.

Olympus Corp. announced Tuesday that its Pennsylvania-based U.S. unit will pay $623.2 million plus interest to end the kickback case in New Jersey. The company also agreed to a corporate-integrity agreement and the appointment of a monitor.

The firm's Latin American medical business will pay $22.8 million to resolve a separate criminal case.

Federal officials said they will drop criminal charges facing both units as part of the settlement.

Olympus says the kickback case involves an investigation of financial relationships with medical business customers and doctors. The probe focused on activities between 2006 and 2011 to induce the sale of Olympus products.