UPDATE 5-Britain, pressed by airlines, may ease rules for vaccinated travellers

* Ryanair launches legal action over restrictions

* UK may make changes for vaccinated travellers

* Airlines want unfettered travel for those vaccinated

* British Airways, other airlines shares rise

* Government policy reviews due later in June
(Adds Ryanair launch legal action)

By Alistair Smout and Sarah Young

LONDON, June 17 (Reuters) - Britain is considering easing
travel rules for double vaccinated people, a move that would
placate airlines which have launched legal action against the
government's curbs on trips abroad.
Airlines are desperate for restrictions to be relaxed in time
for July and the peak season when they make most profits, while
Britain has for now stuck to quarantine rules that deter travel.

Europe's biggest airline Ryanair teamed up with
Manchester Airports Group (MAG) to launch legal action against
Britain over its travel policy. Other airlines could join.

The pair filed papers for judicial review at England's High
Court at about 1200 GMT on Thursday, a spokesman for MAG said.

But Britain has indicated a possible relaxation, with the
Department for Transport saying on Thursday it was considering
how vaccinations could be used for inbound travel.

More than half of British adults have received both doses of
COVID-19 vaccine, putting it far ahead of Europe.

The Daily Telegraph reported Britain was looking to follow
the European Union's move to allow fully vaccinated tourists to
avoid COVID-19 tests and quarantine from July.

"We have commenced work to consider the role of vaccinations
in shaping a different set of health and testing measures for
inbound travel," a government spokesperson said on Thursday.

Shares in airline stocks jumped on hopes of rule changes.
Ryanair and British Airways-owned IAG were up 3%, while
easyJet and holiday group TUI were 4% higher. Jet2
rose 5%.

Peel Hunt analyst Alex Paterson said the government's more
open minded approach represented progress for an industry which
has endured more than 15 months of depressed revenues.

"From the point of view of sentiment that they're saying
they're going to look at this, that is good news," he said.

'OPAQUE' SYSTEM

Ryanair and other airlines have repeatedly called on the
government to allow vaccinated travellers to avoid quarantine,
as well as urging an easing of restrictions to some lower risk
countries like Malta and Spanish and Greek islands.

EasyJet said it was supportive of legal action and would
monitor its progress.

Ryanair's boss Michael O'Leary has said Britain's travel
policy was "a shambles", describing it as an "opaque" system
classifying destinations as green, amber or red, with each
colour carrying progressively tougher rules related to testing
and quarantine.

The government delayed fully reopening the domestic economy
on Monday due to rising infections. But industry hopes have
grown with indications Britain may now soften its stance on
travel.

"This is very welcome news and should represent a meaningful
restart to international travel in the very near future," Jet2
chief executive Steve Heapy said on Thursday.

The safe list of 'green' destinations is due to be updated
on June 24 and the government said in April it would review
travel policy before the end of June.

Jesse Norman, financial secretary to the Treasury, told Sky
News on Thursday that nothing was ruled out on travel rules.

"We are trying to move cautiously and progressively in the
right direction so I wouldn't write anything off at this point,"
he said.

Britain allowed international travel to resume in May, but
nearly all major destinations like Spain, France, Italy and the
United States were left off the 'green' safe list. Those
visiting 'amber' countries must quarantine for 10 days on their
return and take multiple tests. 'Red' countries have tougher
rules.

(Reporting by Alistair Smout and Sarah Young in London and
Akriti Sharma and Juby Babu in Bengaluru; Editing by Guy
Faulconbridge, Raissa Kasolowsky and Edmund Blair)