An advertising agency that helped develop marketing campaigns for OxyContin and other prescription painkillers has agreed to pay U.S. states $350 million rather than face the possibility of trials over its role in the opioid crisis, attorneys general said Thursday.

Publicis Health, part of the Paris-based media conglomerate Publicis Groupe, agreed to pay the entire settlement in the next two months, with most of the money to be used to fight the overdose epidemic.

It is the first advertising company to reach a major settlement over the toll of opioids in the U.S. It faced a lawsuit in at least Massachusetts but settled with most states before they made court claims against it.