The total deficit of U.K. defined benefit funds covered by the Pension Protection Fund's 7800 index increased 9% in March to £135.9 billion ($168.4 billion).
The deficit was £124.6 billion at the end of February.
Deficits also increased over the year ended March 31, from £12.7 billion as of March 31, 2019, said an update by the London-based PPF on Tuesday.
The funding ratio of the corporate pension plans declined over the month to 92.5% as of March 31, down from 93.2% as of Feb. 29. The funding ratio was 99.2% a year ago, the update said.
Assets decreased 2.3% during the month but rose 4% for the year ended March 31, to £1.68 trillion. Liabilities fell 1.6% over the month but increased 11.6% for the year to £1.816 trillion.
The FTSE All-Share index fell 15.1% for the month and 18.5% for the year ended March 31, said the PPF, which is the lifeboat fund for the defined benefit plans of insolvent U.K. companies. Five- to 15-year index-linked gilt yields increased 11 basis points in March, but fell 28 basis points over the year.
As of March 31, 66% of the 5,422 pension funds covered by the index were in deficit, compared with 64% as of Feb. 29. A year ago, 56% of the 5,422 pension funds were in deficit.
