The European Commission said it is "determined to fight and sanction" rate-rigging cartels formed by some banks.
Vice president of competition policy Joaquin Almunia said:
Today's decision sends a clear message that the Commission is determined to fight and sanction these cartels in the financial sector.
Healthy competition and transparency are crucial for financial markets to work properly, at the service of the real economy rather than the interests of a few.
The sanctions - the first from the European Commission on rate manipulation - are the highest yet for European anti-trust enforcement.
More top news
War veteran Paul Royle died at a Perth hospital on Sunday following surgery on a hip fracture.
So-called Corbynmania has officially reached ridiculous new heights - someone has bought a paper coffee cup used by Jeremy Corbyn for £51.
The day will get off to a bright but chilly start, with a few mist patches in rural areas. Showers will spread inland throughout the day.