Banks including JPMorgan Chase & Co. and Citigroup Inc. are set to be fined imminently by the European Union (EU) over collusion on foreign-exchange (FX) trading, according to two people with knowledge of the probe.

The European Commission may announce fines as soon as this week as part of a settlement that sees the lenders get reduced penalties for agreeing not to challenge the findings, the people said on condition of anonymity because the investigation is confidential. EU Competition Commissioner Margrethe Vestager has recently accelerated several probes targeting the financial industry, including one alleging collusion over the trading of government bonds.

Barclays Plc, HSBC Holdings Plc, and UBS Group AG are also among a group of banks that the commission has been investigating for nearly five years, lagging behind the United States, the United Kingdom, and Switzerland, which have already issued about $10 billion in penalties. An American official blasted the companies for a “brazen display of collusion” to game markets in 2015. UBS has said it's been granted conditional immunity by several authorities it didn't identify.