That translated to an average funding level of 76 per cent, down from 84 per cent last year.
The consultancy warned the defined benefit funding crisis showed no signs of abating and companies and trustees must leave "no stone unturned" in their search for a solution.
One such solution, the firm argued, was increased DB transfers, which could "ease the burden of pension schemes deficits and give members valuable options".
The UK's 350 biggest listed companies had a combined deficit of £197bn, more than double the figure a year ago.
The majority - £173bn - of that belonged to FTSE 100 companies.
The figures were calculated using the standard accounting measure (IAS19) used in company reports and accounts, which is generally considered to be a conservative estimate.
For example, according to PwC, at the end of August, the total deficit as calculated by trustees (as opposed to companies) was £710bn.
When calculated as a bulk annuity buyout - that is, the cost of passing the entire UK DB liabilities on to an annuity provider - PwC put the deficit in August at £1.4 trillion.
Charles Cowling, director at JLT Employee Benefits, said funding levels had actually improved somewhat since August (when they were £500m), but nevertheless warned the trend towards bigger deficits would continue.
He said: "Some have argued that in light of unprecedented market conditions, there should be a review of how pension deficits are calculated.
"But this misses the key point that the size of the problem we face today is the inevitable consequence of a regulatory system that is looking to guarantee that members’ benefits are paid.
"If we want those guarantees, and it would take a brave politician to seek to remove them or water them down, then we have to accept that they are very expensive.
"Simply changing the method of measurement solves nothing."
Mr Cowling said DB schemes should consider three routes to improve their funding levels.
The first was a more nimble approach to market risk.
The second was the promotion of "incentive exercise" such as enhanced value transfers - that is, where companies offer members a higher DB transfer value than they need to.
And the third was a more flexible approach to deficit recovery plans.
Of the third approach, Mr Cowling said: "Where there is a strong employer then it is reasonable that the employer be allowed to take more risk, and get more relief, in the funding and investment strategy, through a longer recovery period."
In September, FTAdviser reported that employee benefits consultancies had seen a spike in incentive exercises.
These included enhanced transfer values and “pension increase exchanges” - which see members exchange annual pension increases for a higher initial benefit. Both exercises reduce risk, and are therefore generally seen as desirable by companies.
Last month former pensions minister Steve Webb called on the Financial Conduct Authority to overhaul the regulatory framework for defined benefits transfers.
The FCA currently takes the view that DB transfers will leave most retirees worse off.
But Mr Webb claimed in the post-pension freedoms environment, and with "eye watering" transfer values, this was no longer the case.
His views echoed those of Nigel Chambers, director of pension transfer technology firm CTC Software, who claimed up to 40 per cent of DB scheme members could be better off if they transferred out.
james.fernyhough@ft.com
