UK defined benefit schemes have hit a funding low after combined deficits increased nearly £100bn last month to hit £312bn, statistics show.
The Pension Protection Fund 7800 index, which tracks 6,432 DB schemes in the UK, shows the combined deficit was £312.1bn at the end of May 2012, up from £216.8bn at the end of April.
The figure is the highest deficit since PPF records began in 2003.
PPF figures show total assets were worth £1030.8bn but liabilities had increased to £1343bn, leaving a funding ratio of 76.8% for May, down from 82.6% last month.
It leaves just 929 schemes in surplus compared to 5,503 in deficit.
The reason for the rise in deficits is a 55bps fall in 15 year gilt yields, which has led to a 7.6% increase in liabilities.
Equity market falls over the month also led to a 0.1% drop in combined asset prices.
The PPF collects the data from schemes eligible to enter the fund if a corporate sponsor can no longer fund its scheme.
National Association of Pension Funds chief executive Joanne Segars said: "This is a big leap further into the red for private sector final salary pension funds, and it reflects the immense pressure they are under.
"Cash-strapped businesses that are already struggling to keep these pensions going will have to find more assets to fill in the deficits."
Avoids paperwork with two-step process
Investment process will use machines
Mark Sterling accused of operating a collective investment scheme without authorisation
'Increasing engagement will only favour those prepared to put in the effort'