Swiss-based international trader Gunvor has pleaded guilty to corruption and agreed to pay $661m to settle an investigation into the bribery of officials at Ecuador’s state-owned oil company.

The company was behind a complex bribery scheme for nearly a decade in return for securing deals that ultimately benefited Gunvor, said the US Justice Department.

The company admitted conspiring to violate US bribery laws in a plea deal with the government on Friday.