The CBI states that the European Commission wants to impose a funding regime for pensions, which it claims would force employers to divert billions of Euros into defined benefit pension schemes.
CBI has said that the Commission's aim is to bring the solvency rules for occupational pension schemes in three years' time in line with its so-called "Solvency 2" rules, which will be aimed at strengthening the finances of insurance companies.
This would mean that a company pension scheme would need to cover the full cost of pensions, in case the employer went bust. Normally, a scheme never has to cover the full cost of paying pensions all at once.
The study for the CBI by economic consultants Oxford Economics claims that the changes could result in extra costs of £350 billion over ten years and 180,000 jobs could be lost.
The CBI states the reforms are "wrong-headed" as pension funds, unlike insurance schemes, never have to pay out all benefits at once. Pension liabilities are spread across many years, as workers retire over time and can call on additional funds from employers if needed.
CBI chief policy director, Katja Hall, said: "Imposing £350 billion more costs on business would be a disaster for the economy and for pension saving. The long-term economic outlook is so fragile and uncertain that it is crazy to entertain proposals which would cost jobs and cut so deeply into our long-term growth and competitiveness.
"Workplace pensions are vital to ensuring people have enough money for their retirement when life expectancy is rising - so future generations are not hit with huge bills or driven into poverty. The European Commission's wrong-headed proposal will do nothing to help us cope with the burden of retirement."
Joanne Segars, National Association of Pension Funds (NAPF) chief executive, said: "This report highlights the disastrous impact that the changes would have on UK pensions, businesses and the wider economy. We have been concerned about these plans for a long time, and are alarmed they are still on the table.
"These plans would kick our economy when it is down, and the damage to jobs, growth and living standards would be felt for decades. It is incredible that Brussels wants to strip the business world of £350 billion of potential investment when there are fears of a triple dip recession."
She continued: "Businesses running final salary pensions would be hit with needless extra costs, and would be forced to divert cash away from investment and growth. Many would opt to close their final salary pension schemes altogether, so millions of workers would lose out."
She added: "Europe is pushing for a dangerous solution when there is no problem in the first place. The UK has a very strong system of pension regulation, and there is no need for these ill-conceived rules."
