Toshiba Corp. said Thursday it has filed a suit with the European Union's General Court against the European Commission's earlier decision to fine the firm 13.2 million euro for forming a cartel with six other companies to fix power transformer prices.

The commission made the decision in October, imposing fines on the seven companies, including three Japanese firms, for their infringement of the EU's competition law.

"Following its own investigation, Toshiba contends that it has not found any infringement of EU competition law," Toshiba said in a statement.

But the other two fined Japanese firms — Hitachi Ltd. and Fuji Electric Holdings Co. — said they have decided not to file any appeal against the commission's decision.