Financial Mail has calculated that a company such as BT, whose pension scheme has a big exposure to equities, will have seen the deficit on its fund double to about £4.5bn after the stock market fall in the first half of this year. And BP, which had an FRS17 deficit of nearly £680m at the end of last year, could now be facing a £2.1bn gap, while Marks & Spencer's stated shortfall of £419m will have widened to about £700m.