Shares in Barclays plunged more than 10 percent and Prime Minister David Cameron said the company has "serious questions" to answer on Thursday after the bank was hit by record fines for distorting rates.
Barclays was down 10.28 percent at 175.9 pence in midday deals on London's benchmark FTSE 100 index -- one day after it was revealed that British and US authorities had fined the bank record amounts amid international probes into several top banks.
Barclays bank is to pay $452 million (363 million euros) in fines amid probes into suspected manipulation by several banks of key markets for Libor and Euribor interest rates.
Barclays chief executive Bob Diamond said that in view of this, he and other senior executives at the bank would forego their annual bonuses due for work in 2012.
The Libor and Euribor rates are benchmark reference rates which indicate the interest rate which banks charge when lending to each other. Inter-bank rates affect a vast range of commercial rates for global financial markets, businesses and ordinary consumers.
Asked to comment on the Barclays situation, Cameron told reporters on Thursday that the bank's "whole management team have got some serious questions to answer."