Barclays sought to calm worried investors today by saying the collapse of US energy giant Enron would not have a "material" effect on its business.
The bank omitted any mention of the energy group from a third-quarter update but kept its provision against bad debts for the full-year at £1.1 billion (sterling).
A spokeswoman added: "Enron is not mentioned in the trading statement and while we cannot comment on individual cases I think that tells its own story."
The comments came after speculation over the weekend about the exposure of the UK's leading banks to one of the biggest corporate failures in the US.
Reports suggested high-street banks were owed millions of pounds by Enron's subsidiaries, with Barclays said to be facing a loss of up to £300 million.
Abbey National on Friday revealed it had lent £115 million to the group and said it expected to lose £95 million in the second half.
National Australia Bank, which owns Yorkshire Bank and Clydesdale Bank in the UK, said its total exposure was 200 million dollars (£141 million).
The Barclays' spokeswoman said £300 million would have been a "material" sum, but City analysts said the bank's charge could still be as high as £200 million.
Investors showed their concerns despite Barclays' upbeat tone and the bank's share price fell 50p to £21.00 with its rivals also suffering.
Royal Bank of Scotland, which has refused to comment on the Enron crisis, was also down 18p at £16.07, while Abbey slipped 4 1/2p to 973 1/2p.
Enron filed for Chapter 11 bankruptcy protection in the US last night and said it was in active discussions to secure a credit lifeline.
The Houston-based group also filed a lawsuit against would-be suitor Dynegy for wrongful termination of an $8.4 billion proposed merger.
PA