UPDATE 2-London stocks fall on fears over new coronavirus strain

(For a Reuters live blog on U.S., UK and European stock
markets, click LIVE/ or type LIVE/ in a news window)

* New coronavirus strain 70% more transmissible

* Europe imposes travel ban on UK

* Travel stocks hit by restrictions

* FTSE 100 down 1.7%, FTSE 250 off 2.1%
(Updates to market close)

By Medha Singh

Dec 21 (Reuters) - UK mid-cap stocks suffered their worst
day in 3 months on Monday as stricter curbs to fight a
fast-spreading new strain of the coronavirus prompted travel
bans, worries about food shortages and further economic pain.

The domestically focused FTSE 250 fell 2% as the
latest development in the pandemic added to investors' worries,
with no Brexit trade deal in sight and just 10 days to go until
a transition period expires.

"A contraction was already looking likely in the fourth
quarter and this could now extend into the new year if the
lockdown continues," said Rupert Thompson, chief investment
officer at Kingswood.

Several nations closed their borders to Britain, sending the
blue-chip FTSE 100 down about 1.7% despite a sharp slide
in the pound.

BP and Royal Dutch Shell weighed the most on
the index with Shell also taking a hit after it said it
would write down the value of its oil and gas assets by $3.5
billion to $4.5 billion.

Travel and leisure stocks, including British Airways-owner
IAG, easyJet and InterContinental Hotels Group
, shed between 1% and 8% after countries cut transport
ties with Britain.

"The key to whether the current relatively modest correction
turns into something more serious will be whether the vaccine
roll-out proceeds smoothly and the vaccines prove just as
effective against this new more infectious mutation," Thompson
said.

Although the FTSE 100 has recovered sharply since early
November, the index is on course for the worst year since the
global financial crisis in 2008 as pandemic-driven lockdowns
battered the economy and led to mass layoffs.

Stay-at-home winner Ocado Group jumped by about 6%
while precious metal miners, including Fresnillo, added
1.6% as safe haven demand drove gold prices higher.
(Reporting by Medha Singh and Shivani Kumaresan in Bengaluru;
editing by Barbara Lewis)