HSBC is expected to report another huge write down, of more than $1 billion (£480 million) by some estimates, on its portfolio of high-risk sub-prime mortgages in the United States. The Times

The bank will announce the write down with its third-quarter results for its US division on Wednesday, nine months after its American home loan operation became the first high-profile casualty of the sub-prime meltdown by announcing that its bad debts for 2006 would be $1.8 billion higher than forecast.

So far, Wall Street firms have conceded about $25 billion of such losses.

Since HSBC reported its first write down in February, the group has closed its Decision One sub-prime lending operation, ceased buying high-risk home loans from other lenders and, on Thursday last week, shut its mortgage-backed securities unit, with the loss of about 120 jobs.