The cap was introduced in 2014 after public anger against bankers pocketing large bonuses at a time of austerity and after taxpayers had to bail out lenders in the financial crisis.

Britain failed to stop the cap which limits bonuses to no more than fixed pay or twice that amount with shareholder approval.

The Bank of England, which regulates most of the EU's high earning bankers, has said the cap will force up fixed pay, making it harder for lenders to cut costs in a downturn and thus posing risks to financial stability.

"All in all, the bonus cap did not lead to a material reduction in the overall cost flexibility," the European Banking Authority (EBA) said in its report on pay practices.

The cap has led to a very small increase in the fixed costs and this is only in some institutions.

"The present analysis shows no indication that the so-called bonus cap has a potentially detrimental effect on institutions' financial stability," the EBA added.

Total fixed pay for so-called identified staff who come under the bonus rules was 10.6 billion euros in 2014, or less than 1 percent of banks' capital, and a fraction of the 53.2 billion euros in total profits that year, EBA said.

The Bank of England reiterated on Wednesday that fixed pay at banks has risen markedly as a percentage of total pay since the bonus cap was introduced, which makes it harder to recover pay should financial or conduct risks come to light later on.

The cap and other EU pay rules, such as having to defer a portion of the bonus over several years, generally apply to bankers earning 500,000 euros (393,117 pounds) or more a year.

The EBA report showed that in its first year of application, the bonus cap was largely complied with across the EU.

Tweaks to the EU rules have led to a sharp rise in the number of identified staff.

EU banks employ 2.9 million staff and in 2014 there were 62,787 identified staff, up from 34,060 in the previous year.

The number of high earners, or those pocketing a million euros or more a year, increased from 3,178 in 2013 to 3,865 in 2014, with 2,926 based in Britain.

The number of high earner bankers in Germany fell to 242 in 2014, from 397 in 2013.

(Reporting by Huw Jones; Editing by Mark Potter and David Evans)

By Huw Jones