London's leading shares tumbled into the red as a host of blue chip stocks, led by HSBC, dragged the FTSE 100 30.8 points lower to 4220.
HSBC was among the biggest fallers, losing 16.5p to 800p. Also feeling the pressure were Abbey National down 16.25p at 550.75p, insurer Prudential off 11p to 436.25p and Granada down 2.75p at 105.25p.
Retailer Dixons recovered from an earlier fall to rise a penny to 141p.
There was also better news for energy stocks, which had been hit earlier this week by higher oil prices on the back of Middle East uncertainty.
Scottish & Southern Energy rose 2p to 6376p, United Utilities gained 4p to 532p and Centrica climbed 1.25p to 176.5p.
Elsewhere, pharmaceuticals giant GlaxoSmithKline was out of favour with investors despite announcing it had won US regulatory approval for Levitra - its answer to Viagra. Shares dipped 2p to 1238p.
The negative mood was also affecting shares outside the top flight with department store group Beale down 4.5p to 80.5p after warning of a subdued full year performance after the recent heatwave melted sales.
Among the few stocks attracting attention for positive reasons was air filtration group Domnick Hunter which climbed more than 4% or 16.5p to 388.5p.
The company cheered investors with news of a 16% surge in first half profits to a new record high and strong demand for its products ahead.