News that a member of the EU's Brexit negotiating team is isolating after testing positive for coronavirus, with talks put on on hold, as well as continuing fears over the economic impact of the pandemic hit sentiment.
By the close the FTSE 100 was down 0.8% to 6,334.35, while in the US the S&P 500 was down just barely by 4.30pm UK time at 3,565.46.
Bookmaker William Hill was up 0.6% to 268.4p after shareholders voted this afternoon to approve its takeover by US casino operator Caesars Entertainment for £2.9 billion
AstraZeneca dipped 0.8% to £81.18 as the drugmaker indicated its coronavirus vaccine being developed in partnership with the University of Oxford was safe and triggered a similar immune response among all adults.
Kingfisher fell 2.7% to 291.3p despite reporting that Q3 sales were boosted from a lockdown-fueled rise in home spending demand.
Royal Mail jumped 4% to 297.4p even as the company reported a 90% slump in profit in the first half of the year, but a surge in online shopping boosted parcel deliveries and bolstered its revenue.
Online brokerage CMC Markers gained 1.9% to 402.4p after upgrading its outlook and hiking its interim dividend after profit surged on strong client trading activity.
Geotechnical specialist contractor group Keller upgraded its outlook on full-year outlook following better than expected trading in the second half to date, specifically in North America. Its shares were up 4.9% to 640p
Investment management firm Investec fell 7.9% to 188.1p after the firm halved its interim dividend as first-half profit was hurt by lower revenue amid falling interest rates.
Wine specialist Naked Wines' first-half revenue grew by 80% as demand for home delivery spiked during the first peak of the pandemic. Its shares dipped 0.9% to 494.5p on the news.
Chemicals company Johnson Matthey fell 5% to £24.22 after cutting its dividend and reporting a slump in profit in the first half of the year.
Residential landlord Grainger rose 2.2% to 308.4p as it increased its dividend despite reporting a fall in annual profit as revenue declined amid the impact of the pandemic.