PwC's survey of 150 UK defined benefit (DB) pension schemes with total liabilities of more than £200 billion found that it will take companies around 11 years to repay their pension deficits due to worsening funding positions.
DB schemes, which include "final salary" and "career average" pensions, pay a guaranteed income in retirement, but many have been shut in recent years as firms have found them increasingly expensive to run as people live longer.
PwC warned that companies are having to plough in "considerable amounts of cash" to plug their deficits which could otherwise have been used to help the firm grow or take on more workers as the economy starts to show signs of picking up.
It said that low government bond yields, which are still predominantly used by pension schemes to discount future pension payments, are being blamed for rising pension deficits and the resulting time it will take to pay them off.
Quantitative easing (QE), which allows the Bank of England to inject more money directly into the economy, has been criticised for increasing the burden on DB schemes.
Nearly two-thirds (63%) of schemes PwC surveyed have extended the time it will take to reach full funding by three years or more, to deal with an increased deficit, meaning it will take them until around 2024 to pay off the deficits. In 2010, firms typically had a 10-year recovery plan, meaning they would have got back on track by 2020 rather than 2024.
Paul Kitson, partner in PwC's pensions advisory team, said: "Pension schemes are still suffering from the effects of low gilt yields and an uncertain economic backdrop.
"Despite early signs of economic recovery, companies are still ploughing considerable amounts of cash into their pension scheme just to manage the deficit. This means money that could be reinvested in the business to promote growth, jobs or the strength of the company is too often being tied up in the pension scheme.
"While appropriate funding of UK defined benefit pension schemes is critically important to ensure security for pension scheme members, this increasing cash call on corporate sponsors could be a significant drag on companies' ability to support any potential recovery of the UK economy over the coming years."
Nearly two million people have been automatically enrolled into pension schemes since autumn last year as the Government tries to head off a looming retirement savings crisis.
Those being auto-enrolled are most likely to be placed into a defined contribution (DC) scheme. DC schemes have increasingly replaced DB schemes and they involve the employer shouldering the burden of the eventual size of their pension income.
The Government is looking at possible options for creating more "middle ground" pension schemes, where responsibility for the size of a pension pot would be shared more equally between the employer and the employee. It hopes this will encourage more DB schemes to remain open.