HBOS today admitted it suffered a serious surge in savers withdrawing their cash in the six weeks of September and early October ahead of the Government's bailout and forced takeover by Lloyds TSB.

It said the £8.5 billion new-share placing and £3 billion preference share placing with the Treasury "materially strengthens the group's funding position following deposit outflows in September and in the first half of October, which have now slowed significantly".

But the bank revealed its financial position had deteriorated much more rapidly in the three months from July to September than in the first half of the year. In the first six months, the owner of the Halifax and Bank of Scotland announced writedowns totalling £2.5 billion. In the latest three months it has taken another £2.6 billion hit, making the total for the year so far £5.1 billion.

That is not as high as some analysts had feared, with some predicting up to £5 billion of extra writedowns today. However, HBOS made it clear there are likely to be more charges in the final quarter with losses related to the collapsed Icelandic banks, for example, expected to be £150 million.

The vast bulk of today's writedowns come within the old Bank of Scotland businesses in commercial lending and the bank's treasury department.

HBOS is particularly exposed to the construction and property sectors, where it said an increasing number of customers were operating "under stressed conditions". Write-offs in corporate banking jumped from £469 million at the half-year to £1.25 billion in the last three months.

On the Treasury side, HBOS took advantage of new accounting rules that allow banks to move toxic investments off their trading books into longer-term holdings and avoid huge quarter-by-quarter markdowns on virtually untradeable assets.

But it has still taken a third-quarter writedown of £1.9 billion on that longer-term banking book (£1.9 billion at the half-year). The bank also lost £732 million in the third quarter from "market dislocation", including £457 million of losses related to Lehman Brothers and Washington Mutual.