About 10 per cent of those were trying to re-jig their itineraries so they could leave the Paris leg of their journey until the situation there had settled down, while others were thinking about missing it entirely.
"There are some people who are contemplating giving Paris a miss at this stage, we're talking people who are travelling in the next two to six weeks.
"Then there's others who are looking to change their itineraries so instead of going into Paris and out of Rome they might be seeing if they can rotate that so that they can go to Paris at a later date."
Mr Thomas expected Christmas bookings to be down on usual levels, although he expected things to pick up again come January.
"Subject to the caveat that nothing else untoward happens, we're still expecting strong numbers into France early next year. It's just that instead of booking pre-Christmas some of those people will delay their bookings," he said.
At least 129 people were killed in a series of terrorist attacks in the French city on Friday night (French time).