US banking major Citigroup paid $2.5bn (£1.6bn, €2.2bn) in fines for its involvement in the rigging of foreign exchange markets, while the firm made just $1m from the illegal conduct.

Bloomberg, citing Jamie Forese, head of the Citigroup's Institutional Clients Group that houses trading and investment banking, reported that the bank's fine was 2,500 times more than what it made from FX rigging.

"The misconduct of some of our employees has been hugely painful to the institution and to shareholders," Forese was quoted as saying at an investor conference in New York.

"We are spending a lot of time on improving the conduct of our employees."

In May, Citigroup agreed to pay $925m and pleaded guilty to US charges brought in a probe of the lender's manipulations of the currency markets. In November, the company agreed to pay $1.02bn to three regulators in the US and the UK over the same activity.

Earlier, five banks including Citigroup were levied record fines totalling $5.7bn for rigging foreign exchange markets. The global foreign exchange market is worth £3.5tn a day.

The banks were accused of fixing benchmark foreign exchange rates by colluding in online chat rooms to make transactions simultaneously minutes before rates were set.