General Motors will pay $US900 million ($A1.25 billion) after it failed to recall cars with faulty ignitions that have been linked to 124 deaths.
AFP reports that GM, the largest car maker in the United States knew about the defect for over a decade but took no action.
GM agreed on the settlement and, in exchange, the US agreed not to seek a conviction over the matter. In addition, the company agreed to the appointment of an independent monitor.
"GM admits that it failed to disclose to its US regulator and the public a potentially lethal safety defect that caused airbag non-deployment in certain GM model cars, and that GM further affirmatively misled consumers about the safety of GM cars afflicted by the defect," Federal prosecutors said in a letter to Anton Valukas, who conducted an internal investigation of the case for GM.
The settlement was criticised by US Democratic senators Richard Blumenthal of Connecticut and Edward Markey of Massachusetts.
They said in a joint statement that the penalty should have been larger and that there should have been a criminal acknowledgment from the company.
"GM knowingly concealed information that could have prevented these deaths, and it is shameful that they will not be held fully accountable for their wrongdoings," the statement said.
Laura Christian, whose 16 year old daughter died in a Chevy Cobalt fitted with one of the faulty ignitions 10 years ago, said someone from GM should have gone to prison.
"I just feel bad for all the other parents out there… that never will feel they have received true justice," Christian told CBS News.
In 2014, GM sacked 15 executives over the scandal.