Top bosses are closing staff pension schemes while keeping their own pension plans open, a survey from financial firm Origen has suggested.
Firms have trimmed staff pensions to cut costs
Over the past four years there has been a dramatic fall in the number of final salary schemes open to new staff.
But there has been just a 5% fall in the number of these schemes open to senior executives, the study found.
In the past, unions have accused bosses of operating a "two-tier" pensions strategy for their own benefit.
Final salary pension schemes are seen as more lucrative. They promise to pay a pension based on a combination of length of service and earnings in the final year before retirement.
But these schemes can be expensive for employers to fund and as a result increasing numbers have been closed to new joiners.
Instead, new staff are being moved into money purchase schemes, where the eventual retirement income is based on contribution levels and the investment performance of pension funds.
The study by Origen found that employers were paying an average of 7% of staff's pay into a money purchase scheme - about half the average paid into a final salary scheme.
Origen said the lower level of contributions could have a serious impact on retirement incomes.
It said contributions of 7% were likely to provide a pension of only about 15% of a worker's pre-retirement earnings, if the worker joined at age 40 and retired at 65.
But Origen added that the amount of money firms were paying into money purchase pensions was on the rise.
"We can conclude that concerns about contribution levels being too low are beginning to hit home," said Michelle Cracknell, business development director at Origen.