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FTSE 100 down 0.4%, FTSE 250 falls 0.6%

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UK retail sales contract in October, business growth

stalls in

November

Nov 21 (Reuters) - London's main stock indexes plunged

on Friday, headed for weekly losses, as concerns over tech

valuations and Federal Reserve's hawkish stance rattled global

markets, while defence shares slid amid signs of potential

progress toward peace in Ukraine.

As of 1222 GMT, the blue-chip FTSE 100 index fell

0.4%, erasing Thursday's brief recovery, while the mid-cap FTSE

250 index dropped 0.6%, on pace to extend its losing

streak to an eighth consecutive session.

Thursday's global rally following chip bellwether Nvidia's ( NVDA )

upbeat forecast proved short-lived as worries of a

potential AI bubble resurfaced and a mixed U.S. jobs report left

Fed rate-cut prospects unclear.

Both UK stock indexes poised to register even steeper weekly

losses than those seen in April, when markets were roiled by

U.S. President Donald Trump's sweeping tariff announcements.

Aerospace and defence stocks fell 3.2% on the

day to their lowest in three months, as investors monitored

developments around a new U.S.-drafted plan to end the Russian

war in Ukraine.

Defence and engineering contractor Babcock dropped

0.7% even after it reported a 19% jump in first-half profit and

forecast further growth this year.

Banking stocks drifted lower by 0.7%, with

heavyweights HSBC Holdings ( HSBC ) and Barclays ( BCS )

dropping about 1%.

Precious metal miners lost 3.6% as gold

prices retreated more than 1%, while industrial metal miners

declined 1.7% after copper prices sank to their

lowest level in over two weeks.

Domestic economic data also added to the gloom. Retail sales

contracted in October alongside weakening household sentiment,

while business growth stalled as November's PMI dropped.

Companies are now awaiting next week's budget announcement,

where finance minister Rachel Reeves is expected to implement

additional tax increases.

Among individual movers, fast-fashion retailer ASOS

plunged 8.7% after the company forecast lower annual profit than

analysts' expectations.