One month after the European antitrust regulators charged Deutsche Bank, Credit Agricole and Credit Suisse of being a part of a 'bond trading cartel', regulators are bringing a separate case against eight unidentified European banks alleging that they conspired to rigging euro-denominated sovereign bond markets.

Reuters reported Thursday that the European Union's antitrust authority has charged the banks with operating the cartel behind 2007 and 2012.

Just like in past cartel cases, traders at the accused banks allegedly used chat rooms to share "commercially sensitive information and coordinated trading strategies" that they presumably used to rig markets to benefit their own trading books - and shortchange their "counterparties".

If they're found guilty, the banks could face fines equal to up to 10% of their global turnover.

"The Commission has concerns that, at different periods between 2007 and 2012, the eight banks participated in a collusive scheme that aimed at distorting competition when acquiring and trading European government bonds," the Commission said.