The South Korean financial regulator said Tuesday it has slapped a 2 billion-won ($1.8 million) fine on Woori Bank, the banking affiliate of state-run Woori Finance Holdings Co., for failing to notice suspected slush funds at food-focused conglomerate CJ.

The penalty comes as Woori Bank did not report some 300 bank transactions by CJ between September 2009 and May 2013 that are suspected as money laundering attempts, said the Financial Intelligence Unit, an affiliate of the Financial Services Commission.

Financial firms are mandated to clarify suspicious bank transactions and report them to the FIU in case they are money laundering moves.

"On top of the bolstered rule, there were signs that Woori Bank deliberately did not report the suspected transactions, which led to a relatively large fine," said a FIU official. (Yonhap)