According the data published yesterday, the estimated aggregate for the DB schemes of FTSE350 companies stood at £42 billion (equivalent to a funding ratio of 92%) at 30 September 2012.
This compares to a deficit figure of £63 billion at the end of August and a figure of £61 billion at the end of December 2011, on a like-for-like basis.
Over the last 10 years, the data, which is taken from FTSE350 company accounts, also found average scheme funding levels have improved from 79% in 2002 to 80% in 2012. But an estimated £175 billion, or 40% of the average asset value, in deficit contributions have been paid over the same period.
Mercer's head of DB risk in the UK, Ali Tayyebi said: "This is good news for companies sponsoring DB pension schemes. As we near the year-end reporting period. The two key factors, which drive the calculation of liabilities, have both moved in a favourable direction.
He added: "September has been the stand out positive month this year so far, but experience shows that the factors causing the improvement could reverse just as easily."
Adrian Hartshorn, Partner in Mercer's Financial Strategy Group said: Mercer estimates the aggregate combined funded ratio of plans operated by FTSE350 companies on a monthly basis. This is based on projections of their reported financial statements adjusted from each company's financial year-end in line with financial indices.
