The pension deficit at the UK's largest companies has grown slightly, according to a report by pensions expert LCP.
Its annual report shows the gap between assets and liabilities in defined pension schemes widened from £42bn to £43bn in the year to the end of June.
This was despite an increase in funding and a rising stock market.
The main cause was continuing low interest rates, which affect the calculation of a pension scheme's future liabilities.
LCP's Accounting for Pensions report, which looks at the pension schemes of the FTSE 100 companies, also found that rising life expectancy has added £40bn to liabilities over the last eight years.
The report also looked back over the past 20 years.
Even though share prices are rising and employers put £22bn more into their schemes, a deficit of £43bn remains.
Final salary schemes
This means that the average FTSE 100 pension scheme's assets today can cover 91% of its liabilities.
Twenty years ago, that figure was 120% and companies were able to enjoy contribution "holidays".
LCP also pointed out that 20 years ago, virtually all FTSE 100 companies offered a final salary scheme. Today, no FTSE 100 company offers such schemes to new employees.
LCP notes that auto-enrolment is back, having disappeared from the pension landscape in 1988.
LCP partner and the report's author, Bob Scott, said that FTSE 100 companies now disclose much more about the state of their pension schemes in their annual accounts, compared with 20 years ago.
He added that going forward companies would be aiming and hoping to "completely remove any pensions risk from their balance sheets".
"This may be good news for their shareholders but is unlikely to improve the lot of those employees who are relying on good workplace pensions for their retirement," he said.