Barclays has been slapped with total fines of £290m for its "serious, widespread" role in manipulating the price of crucial interest rates in a move that has forced chief executive Bob Diamond and other top executives to forgo any bonuses for 2012.

The £59.5m fine from the Financial Services Authority is the largest penalty ever levied by the City regulator, which found that Barclays contravened its rules for a number of years and involved "a significant number of employees".

The other penalties paid by Barclays are to settle with the US authorities, the department of justice ($200m) and the Commodities Futures Trading Commission ($160m), as part of an industry wide probe into the way that interest rates traded between banks were set.

The investigation covered the London Interbank Offered Rate (Libor) and the Euro Interbank Offered Rate (Euribor) both of which play a critical role in setting the rates of interest that households and major companies pay to borrow.