Stagecoach, whose megabus.com services operate between British and European cities including Paris, said it believed the attacks which killed 130 people in the French capital on November 13, had discouraged people from taking trips.
The rate of revenue growth in parts of its inter-city coach business and its UK rail units which connect with London, Manchester and Edinburgh, had dropped over the last month, Stagecoach said, prompting it to modestly cut its adjusted earnings per share guidance for the year ended April 30.
The downgrade was also connected to the softer than expected revenue at a number of its regional bus businesses in Britain, Stagecoach added.
Analysts currently expect Stagecoach to report annual earnings per share of 29.3 pence according to a poll.
The company said it expected a recovery in revenue growth rates as travel between major cities picked up again.
For the six months ended October 31, Stagecoach reported adjusted earnings per share of 17 pence, 13 per cent higher than the same period last year.