The U.S. Department of Justice and Environmental Protection Agency has announced a settlement with Korean automakers Hyundai and Kia over allegations the two violated the Clean Air Act.

A filed complaint alleges both companies inflated the fuel economy ratings in about 1.2 million vehicles. 

That resulted in greenhouse gas emission credits worth more than $200 million. 

U.S. Attorney General Eric Holder outlined details of Monday's settlement, which includes:

• Hyundai and Kia will pay a civil penalty of $100 million dollars, which is the largest civil penalty ever secured under the Clean Air Act. 
• Both companies will forfeit the greenhouse gas credits both wrongly claimed based on inaccurate reporting.
• Hyundai and Kia will be required to implement rigorous new procedures, including training and enhanced audit testing of vehicles to prevent the violation from happening again.