The European Commission censured seven investment banks for maintaining a cartel on European government bond-trading. The Swiss bank was hit with the largest fine, despite cooperating.

Brussels extracted a total of 371 million euros ($453 million) on UBS, UniCredit, and Nomura for a seven-bank ring which colluded between 2007 and 2011 on prices and volumes of European government bonds, the commission said in a statement on Thursday.

The other banks censured in the cartel were not fined: Natwest had blown the whistle on it, while Bank of America and Natixis escaped because their wrong-doing fell outside of a time period for which fines could be levied. Lastly, WestLB, now Portigon, generated zero revenue from the scheme in the last business year, capping its potential fine at nil.

Weighing Appeal

UBS, which racked up the biggest fine (174.2 million euros), told domestic agency «AWP» (in German) that it is considering an appeal. The fine will take roughly $100 million out of UBS' second-quarter results, it said.

The Swiss bank's fine would have been 45 percent higher had it not cooperated with the commission, overseen by Brussels' anti-trust chief Margrethe Vestager. The commission fined Nomura 130 million euros and Italy's Unicredit, now run by UBS' former top investment banker Andrea Orcel, 69 million euros.