Defined benefit schemes saw an increase of more than £170bn in total deficits in 2009, marking the worst year on record, Pension Capital Strategies (PCS) says.
PCS estimated all UK private sector pension schemes had a deficit of £212bn as at 31 December, representing a funding level of 81%.
The firm says this compares with a £37bn deficit in the previous year, marking a 96% funding level.
It also showed FTSE 350 companies had a £80bn deficit, with assets of £460bn and liabilities of £80bn.
PCS managing director Charles Cowling says: "2009 has not been a good year for UK pension schemes. Indeed the increase of £170bn in the total deficit is the worst calendar year performance on record."
He says despite strong investment returns in equities among other asset classes, pension deficits rose sharply as liabilities surpassed investments.
PCS says it was largely due to reductions in AA bond yields used to value pension liabilities, as well as increased inflation expectations.
Cowling adds: "We believe 2010 could mark a turning point for employers as liability reduction measures become normal and the closure of DB schemes to all employees accelerates, thus capping the growth in new liabilities.
"2010 therefore holds up the prospect of being the year when UK plc finally turned the corner in the management of its pension liabilties."
Created by 150 individuals
Investor urges fund group to be more cautious on promoting funds
Ahead of 12 December general election
Demerger expected to complete in Q1 2020
Engaging with finances