United Parcel Service has agreed to forfeit $40 million that it earned from illegal Internet pharmacies that shipped drugs using U.P.S. services, federal authorities said on Friday.

As part of the settlement, U.P.S. entered a nonprosecution agreement with the Justice Department.

The company also agreed to put a compliance program into place to prevent illegal online pharmacies from distributing drugs through its shipping services, the authorities said.

“Good corporate citizens like U.P.S. play an important role in halting the flow of illegal drugs that degrade our nation’s communities,” Melinda Haag, a United States attorney for the Northern District of California, said in a statement.

U.P.S. cooperated with the investigation, the prosecutors said.

Prosecutors said U.P.S. was on notice from 2003 to 2010 that Internet pharmacies were shipping drugs without prescriptions, yet the company did not put procedures in place to shut down their accounts.

“We believe we have an obligation and responsibility to help curb the sale and shipment of drugs sold through illegal Internet pharmacies,” said Susan Rosenberg, a U.P.S. spokeswoman.