Shares in airlines and travel companies hit turbulence today after a profits warning from low-cost carrier Ryanair.
The wider London market was also under pressure amid ongoing concerns over the prospect of military intervention in Syria.
The FTSE 100 Index dipped 32.9 points to 6435.5 and other European markets were squeezed after two senior Republicans gave a major boost to President Obama's hopes of getting approval for a military strike.
London's decline came despite more encouraging news on the UK economy, with new figures showing that the powerhouse services sector accelerated at its fastest pace for more than six years in August.
But most of the attention was on the travel sector after Ryanair's warning over headwinds this winter, including from greater competition and the impact of Europe's ongoing economic crisis.
It will axe some services and has cut its passenger target for this financial year from 81.5 million to just under 81 million, meaning its profits will be towards the bottom end of its current guidance.
Dublin-listed Ryanair's shares were 13% lower, while rival easyJet was the biggest faller in London's top flight, off 6% or 80.5p to 1199.5p.
British Airways parent company International Airlines Group fell 9.45p to 285.25p and Thomson Holidays owner TUI Travel declined 14.3p to 331.5p. Outside the top flight, Thomas Cook was down 7.6p to 135p, or 6%.
Other big fallers included financial services firm Hargreaves Lansdown, even though it posted a 28% rise in full-yer profits and said active client numbers were at a record level. Shares dipped 18p to 1013p as investors booked profits following a strong run for the Bristol-based company.
Meanwhile, Vodafone shares continued to see-saw in the wake of Monday's £84 billion deal to sell a 45% stake in Verizon Wireless.
The heavyweight stock, which declined yesterday after a week of big rises, was back in positive territory, up 3.7p to 206.2p.
Other companies on a shortened risers board included Costa owner Whitbread, which added 36p to 3154p ahead of a trading update next week.
Shares in Argos and Homebase owner Home Retail Group were flat at 144.2p after the company announced that chief executive Terry Duddy will leave the company by next July.
He took the helm of Argos in 1998 after mail order retailer GUS, Home Retail's predecessor, bought the catalogue business for £1.9 billion.