Ryanair, the European low-cost airline, said yesterday that in the four days following last Thursday's bombings in London, forward bookings had fallen by "just under 10 per cent" from the level of recent weeks.
Michael O'Leary, chief executive, said advance bookings were down about 8,000 a day from the expected level of more than 100,000 a day. A breakdown of bookings was not yet available, but he said: "I assume a lot of this is inbound travel to London."
The Irish airline's main base is London Stansted airport, which accounts for about 30 per cent of its traffic, more than half of which originates from abroad.
Building on its experience in the wake of the September 11 2001 terrorist attacks in the US, Ryanair is launching a big discounted seat sale to counter any longer-term weakness in bookings.
The airline said it was bringing forward from September to mid-July a planned sale of 3m discounted seats (at £1/€1 per seat plus taxes).
The carrier is launching an immediate £5m ($8.8m) pan-European advertising campaign featuring London and other other UK cities. It was "more important than ever" that leading participants in London and UK tourism made it attractive to visit London this autumn, said Mr O'Leary.
The airline had also suffered a dip in bookings after the Madrid train bombings and the Bali bombing, both destinations to which Ryanair does not fly.
"There is some hit for the first couple of days and then afterwards it picks up," said Mr O'Leary. "We don't know if this will also have some impact in the medium term, because this is London."
Ryanair left its financial guidance for the year unchanged, a stance repeated by other aviation groups including easyJet, British Airways and BAA, the airports group, which includes Heathrow, Gatwick and Stansted.
EasyJet said it was too early to assess the long-term impact of the bombings on its traffic but added that more than 10,000 of its passengers had rebooked their flights from last Thursday/ Friday to later dates.
BA said there had been "some fall-off in bookings" last Thursday, but demand was now "back in line with where we would expect it".
BAA said: "We would expect a very small blip [in passenger traffic] and then a rapid recovery." Successively, the initial decline in passenger numbers had become smaller and shorter-lived after the 1991 Gulf War, after 9/11 and after the 2003 Iraq war.
