The FTSE 100 of Britain's leading shares fell 0.7 per cent this morning as the credit crisis continued to overshadow markets.
Earlier this morning, the FTSE 100 was down 46.8 points at 6,317.1 as traders looked to US retail sales data for later in the session for further direction.
Shares in Northern Rock plunged 21.75 per cent to 500 pence in early trading this morning after the bank said it was expecting lower pretax profit of £500 million to £540 million, compared with analysts' current consensus forecast of £647 million.
The bank was offered an emergency loan from the Bank of England, becoming the biggest British casualty so far of the crisis squeeze, which has hit global markets.
Among fellow lenders, Alliance & Leicester, HBOS and Bradford & Bingley all fell.
HSBC Holdings shed 0.3 per cent after a newspaper reported that it is in talks to buy a 49 per cent stake in the life insurance unit of South Korea's Hana Financial Group.
Barclays was 2.4 per cent lower as it prepares to hold a shareholders meeting to approve support for its bid for Dutch rival ABN Amro.
In commodities, US crude prices rose to about $79 a barrel as a hurricane subsided in the gulf of Mexico, though prices held near the previous day's record high on supply worries ahead of the peak winter period.
But higher metal prices boosted miners, with BHP Billiton, Anglo American and Xstrata all trading higher.