Trading in all stocks and derivatives on Euronext markets, including the stock exchange in Dublin, shut down for three hours on Monday morning, the biggest outage to hit the exchange operator in two years.
Stocks such as L'Oreal SA, LVMH and Kering in Paris were halted, with other Euronext markets in Belgium, the Netherlands and Portugal also affected. Companies on the affected exchanges make up about 22 per cent of the components in the benchmark Stoxx 600 index.
Wall Street's main indexes slipped as losses in tech heavyweights Facebook and Amazon eclipsed optimism on a coronavirus relief deal before the presidential election.
The Iseq index slipped by 0.2 per cent in heavily disrupted trading.
The banks performed poorly, as pessimism over the potential consequences of another near-lockdown began to seep in. AIB finished the session down by 2.75 per cent to 92 cents per share, while Bank of Ireland fell 1.1 per cent to €1.83.
Ryanair continued its mercurial recent run, regaining some of its lost ground with a 4.1 per cent rise to €12.15 per share, as the airline prepares to shutter some bases for winter including Cork and Shannon.
Hostelworld rose almost 10 per cent to 55 cent per share as the budget accommodation terminal's forecasts were upgraded.
British midcaps edged higher on signs that Brexit-trade talks between the UK and European Union were intensifying, although gains were capped due to concerns over tougher business restrictions in Britain.
The FTSE 250 index, considered a barometer for Brexit sentiment, closed 0.2 per cent up, boosted by shares of flexible office space provider IWG which jumped 5 per cent after Berenberg upgraded the stock to "buy".
After rising nearly 0.7 per cent in early trading, the blue-chip FTSE 100 ended 0.6 per cent lower, dragged down by shares of Reckitt Benckiser, pharmaceutical and personal goods maker stocks. A stronger pound pressured exporters.
Amigo Holdings tumbled 10.6 per cent after saying it had entered an Asset Voluntary Requirement (AVR) with Britain's financial watchdog, meaning the subprime lender will need approval to transfer assets outside of the group.
European shares ended lower as surging Covid-19 cases raised the possibility of further economic restrictions, outweighing optimism from signs of progress on a Brexit trade deal and hopes of fiscal stimulus in the US.
Tech major SAP weighed on Germany's DAX, while France CAC 40 turned to losses at close. The pan-European Stoxx 600 index closed down 0.3 per cent after trading flat in the second half.
At the top of Stoxx 600 was Swiss wealth manager Julius Baer which jumped 6 per cent after it indicated an improvement in profitability for the first nine months of 2020. The broader financial services sector rose 1 per cent, with Credit Suisse and UBS rising 4.4 per cent and 3 per cent, respectively.
Nokia posted its best session in over two months after it was selected by Nasa to build the first cellular network on the moon. Swedish defence company Saab sank 14.3 per cent after it reported a fall in third-quarter profit and could not confirm its previous financial outlook for the year.
Amazon.com, Facebook and Microsoft fell between 0.8 per cent and 1 per cent. They were among the biggest drags on the S&P 500. All major S&P sectors were lower, with the communication services index down 1 per cent.
Video-streaming service Netflix was a bright spot, rising 1.2 per cent ahead of its results on Tuesday.
Oilfield services provider Halliburton posted a fourth consecutive quarterly loss as this year's slump in oil prices due to the Covid-19 pandemic hit demand for its services. Its shares, however, rose about 3.3 per cent.
ConocoPhillips slipped 0.1 per cent as it agreed to buy US shale oil producer Concho Resources for $9.7 billion as the energy sector continued to consolidate.
Concho fell 0.9 per cent. Chipmaker Microchip Technology gained about 1.6 per cent after Morgan Stanley upgraded the stock to "overweight".
(Additional reporting: Reuters)