The FTSE 100 index was 0.4pc lower by 0805 GMT and was set to end the week with a near 1pc fall, but the midcap bourse rose 0.1pc as it drew strength from the pound.
As the epidemic in China shows no signs of peaking, global markets may look to central banks to step in and undertake stimulus measures. Last week, U.S. Federal Reserve Chair Jerome Powell had warned that economic impact from the virus in China could spill over globally.
Among corporate news, AstraZeneca dropped nearly 4pc, its steepest one-day fall since July 2017, as its quarterly earnings failed to match up to market expectations.
Royal Bank of Scotland fell 3.4pc after its new top boss set out a new strategy that included cutting back the size of its loss-making investment bank and renaming the company NatWest.