British Airways said it had cancelled seventy flights planned for today after security officers at Heathrow started ten-day strike action.
Union Unite said the action involves its members working at Terminal 5, which is exclusively used by British Airways.
Heathrow said it had offered a 10% pay increase back-dated to 1 January, plus a lump sum payment of more than £1,000.
Even so, analysts at Deutsche Bank upgraded the airline’s owner IAG because the outlook for the sector had "materially improved".
IAG’s price target is now 200p from 180p, Air France €2.3 from €1.75 and Deutsche Lufthansa €14 from €10.5.
Analyst Jamie Rowbotham said it had upgraded the trio even though he had been prudent on yields, non-fuel unit costs and on oil itself.
"We nonetheless see the potential for operating profits in 2023 to now be more than 20% higher than we previously envisaged, and ~18% above current Bloomberg consensus estimates on average."
Analysts at Barclays have also taken a more positive view of IAG, upgrading to overweight from neutral.
Barclays made a similar move on easyJet as well with its shares rallying 4% to 521p.
Shares in IAG rose 1.9% to 151.6p, Air-France jumped 3.2% and Deutsche Lufthansa firmed 2%.