UPDATE 2-UK shares steady as vaccine cheer offsets fears about new restrictions

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* Berkeley Group jumps on raised annual profit outlook

* Airline stocks hit by worries of travel restrictions

* TUI falls on posting FY loss of over 2 billion euros

* FTSE 100 adds 0.2%, FTSE 250 up 0.1%
(Updates prices, adds details on possible restrictions)

By Bansari Mayur Kamdar and Shashank Nayar

Dec 8 (Reuters) - UK's main stock indexes gained on
Wednesday after hitting session lows as positive headlines on
COVID-19 vaccines helped offset concerns about Britain
implementing tougher COVID-19 measures as early as Thursday.

The blue-chip FTSE 100 turned negative before rising
0.2% as a fall in sterling to fresh 2021 lows boosted the
exporter-heavy index.

Several media reports said Prime Minister Boris Johnson
might announce as soon as Wednesday a new coronavirus Plan B
which could include advice to work from home and COVID passports
for large venues.

However, markets were quick to reverse losses after BioNTech
and Pfizer said that a three-shot course of
their COVID-19 vaccine showed a neutralising effect against the
new Omicron variant in a laboratory test.

"The Pfizer news is feeding into that more positive picture
that's being built around Omicron," said Craig Erlam, senior
market analyst at Oanda.

"This idea is that it's not all doom and gloom, just because
this variant is more vaccine resistant, it doesn't mean the
vaccines are now useless, is building a more positive picture
than what we were facing a week last Friday," Erlam added.

The mid-cap FTSE 250 index advanced 0.1%, but
weakness in pub and restaurant stocks including Mitchells and
Butlers, JD Wetherspoon and Restaurant Group
, all down between 1.7% and 4.5%, limited further gains.

Cineworld dropped 5.1% and was the top loser on the
travel and leisure sub-index, while British
airline stocks Wizz Air, Easyjet and British
Airways owner IAG fall more than 3% each.

UK's benchmark FTSE 100 has rebounded to levels seen before
the detection of the Omicron variant in late-November, as
experts say the new strain might not be as severe as feared.

Tour operator TUI declined 0.8% after it posted an
annual loss of over 2 billion euros ($2.26 billion).

Homebuilder Berkeley Group Holdings added 4.2% as
it raised annual profit outlook after sales recovered to
pre-pandemic levels.
(Reporting by Bansari Mayur Kamdar in Bengaluru; Editing by
Subhranshu Sahu, Uttaresh.V, William Maclean)