The total deficit of U.K. defined benefit funds covered by the Pension Protection Fund's 7800 index increased 18.2% in September, to £166.1 billion ($213.6 billion).
The deficit was £140.5 billion at the end of August.
Deficits also worsened for the year ended Sept. 30, from £117.6 billion, said an update Tuesday by the London-based PPF. The PPF is the lifeboat fund for the defined benefit plans of insolvent U.K. companies.
The funding ratio of the corporate pension plans worsened to 91.4% as of Sept. 30, down from 92.6% as of Aug. 31. The funding ratio was 93.6% as of Sept. 30, 2019, the update said.
Assets were up 0.94% during the month and rose 2.2% for the year ended Sept. 30, to £1.77 trillion.
Liabilities increased 2.2% over the month and increased 4.7% for the year, to £1.94 trillion.
The FTSE All-Share index was down 1.7% for the month and fell 16.6% for the year ended Sept. 30, the PPF said. Five- to 15-year index-linked gilt yields decreased 10 basis points in September and declined 9 basis points over the year.
As of Sept. 30, 66.2% of the 5,422 pension funds covered by the index were in deficit, compared with 64.7% as of Aug. 31. A year ago, 63% of the 5,422 pension funds were in deficit.