May force many pension schemes to close
This could hamper companies' ability to invest and also force some pension schemes to close.
The estimate from the European Insurance and Occupational Pensions Authority (EIOPA) shows the impact of new capital requirements on final salary-linked pension schemes, where benefits are based on salary and duration of employment.
The 450 billion pound estimate is in line with a worst-case scenario contained in figures the United Kingdom Pensions Regulator produced for the British government last year.
"This confirms that any such new rules would harm businesses' ability to invest, grow and create jobs, and many more (pension) schemes could be forced to close," Minister of State for Pensions Steve Webb said in a statement.
The British pensions industry was also critical.
The National Association of Pension Funds (NAPF) said the high price tag would have a highly damaging effect for the retirement prospects of millions of U.K. workers.
"Businesses trying to run final salary pensions could be faced with bigger pensions bills to plug an astonishing 450 billion pound funding gap," Joanne Segars, chief executive at the NAPF, said.
The new capital rules, known as Solvency II, were originally aimed at the insurance industry but the European regulator is proposing to adapt them for the pensions sector to improve standards of governance, risk management, valuation and calculation of minimum capital requirements.
Britain had the highest funding requirement out of the countries covered in the European watchdog's assessment, which were Belgium, Germany, Denmark, Ireland, the Netherlands, Norway and Sweden.
