European Union (EU) antitrust authorities on Wednesday decided to fine eight international banks a total of 1.7 billion euros (2.3 billion U.S. dollars) for participating in illegal cartels in markets for financial derivatives rates. According to an EU statement, four of these institutions participated in a cartel relating to interest rate derivatives denominated in the euro currency. Six of them participated in one or more bilateral cartels relating to interest rate derivatives denominated in the Japanese yen. Both decisions were adopted under the Commission's cartel settlement procedure. The companies' fines were reduced by 10 percent for agreeing to settle. The EU said such collusion between competitors was prohibited by Article 101 of the Treaty on the Functioning of the European Union and Article 53 of the European Economic Area Agreement. Derivatives are contracts traded on financial markets that are used to transfer risk. "They are of key importance for the European economy," the EU statement read. Besides these two cases, the EU has carried out inspections concerning possible collusion to manipulate benchmarks in the field of oil and biofuels.