UPDATE 2-Cocktail of virus fears, dull earnings, BoE move drown FTSE 100

* FTSE 100 down 1.4%, FTSE 250 down 0.9%
* China-linked virus has so far killed 170 people
* WHO to decide if virus constitutes global emergency
* Shell, BT lead losses on main board
* BoE keeps rates unchanged

(Adds news items, updates to closing prices)
By Shashwat Awasthi and Muvija M
Jan 30 (Reuters) - UK shares tumbled on Thursday as the
rising death toll from the coronavirus outbreak led investors
away from risky assets like stocks and at home the Bank of
England kept interest rates unchanged, while Shell and BT slid
on disappointing earnings.
The main index .FTSE fell by 1.4% to levels not seen since
mid-December and the FTSE 250 .FTMC slid 0.9%, as a modest
rebound that the indexes had managed over the last two sessions
unravelled.
Countries have begun isolating hundreds of citizens
evacuated from the Chinese city of Wuhan to stop the virus from
spreading, and the World Health Organization may on Thursday
reassess its stance on the outbreak. "Fears of a pandemic may be over-egging the pudding, but
there is again a clear risk-off mood in the market," Markets.com
analyst Neil Wilson said.
The FTSE 100 has shed nearly 4% since last week when news of
the coronavirus flare-up first emerged.
"Expect to see further declines and more volatility in risk
assets in the coming days. Investors who were waiting for the
dips to buy may need to wait a little longer," FXTM analyst Han
Tan said.
News that England's central bank chose not to cut interest
rates at Governor Mark Carney's final policy meeting lifted
sterling and in turn accelerated losses for dollar earners.
"Carney ended up giving the pound a goodbye kiss rather than
kick, the Bank of England voting to keep interest rates
unchanged, booting any potential cut into the Andrew Bailey
era," Spreadex analyst Connor Campbell wrote.
The biggest drag to the blue-chip bourse came from Shell
RDSa.L , which slid 4.4% to its lowest level since July 2017
after fourth-quarter profit halved and the oil major cut the
pace of its $25 billion share buyback programme. Weaker crude prices also weighed on shares of Shell and peer
BP BP.L , as oil stocks made up more than half of the blue-chip
bourse's losses. O/R
Telecom firm BT BT.L slumped 8% on its worst day in three
years after it reported a steeper-than-expected drop in
quarterly revenue and said Britain's decision to limit Huawei's
HWT.UL role in building 5G and fibre networks would bump up
costs.
Around midday, travel group Carnival's CCL.L UK-listed
stock stumbled as much as 11% to a three-low year after news of
potential coronavirus infection on one of its cruise ships.
Shares ended down 5.1%. Outperforming the main index was Unilever ULVR.L , which
added 2% after the consumer goods company launched a strategic
review of its tea business. Midcap Avast AVST.L dropped 13.5%, bringing weekly losses
to about 30%, after saying it would shutter its data analytics
business following reports of data privacy concerns.