Leading energy trader Gunvor agreed Friday to pay more than $661 million to US and Swiss authorities to settle a case involving bribery of public intermediaries to obtain contracts in Ecuador.

The Swiss firm said it "has accepted responsibility for the actions of certain of its former agents and employees -- all of whom Gunvor stopped working with years ago and before it learned of the US investigation".

Gunvor pled guilty in a New York court on Friday and under the terms of the US resolution will "pay a $374,560,071 fine and forfeit $287,138,444".

"The resolution recognises Gunvor's extensive cooperation with the US Department of Justice's investigation, which led to a significant reduction of the company's fine, as well as the efforts Gunvor has made to strengthen its compliance program," a statement added.

Switzerland's federal public prosecution announced that regulators would receive almost 87 million Swiss francs (around $98 million) from the overall settlement.

A Gunvor spokesman also said Ecuador authorities would also receive part of the settlement, though the amount had not yet been finalised.

In Washington, the Department of Justice noted that Gunvor would pay more than $661 million in fines.

"Gunvor's guilty plea stemmed from the company's corrupt scheme to pay substantial bribes to Ecuadorean government officials to secure business with Ecuador's state-owned and state-controlled oil company, Petroecuador," it said.

The Geneva-based group's chairman, Torbjorn Tornqvist, said: "As a company Gunvor made mistakes at the time, for which we are sorry and that we have worked diligently to fix.

"Today, Gunvor upholds an industry-leading compliance program that we are committed to continuously enhance. Corruption has no place in our company and will never be tolerated."