Up to 90 per cent of conference and incentive travel from the United States to Ireland has been cancelled following last week's atrocity, according to tourism industry sources.

And Aer Lingus's dropping of key transatlantic routes will also impinge on tourist numbers from North America, which accounted for one-quarter of the total tourism spend here in 2000.

The first feed of information from Bord Fβilte offices around the world and from business sources will be presented to a board meeting of the tourism body this morning.

Conference and incentive travel accounts form a major segment of the inward autumn business from North America. But this essentially is discretionary and quite a number of operators have cancelled. Groups travelling to the Ryder Cup, with planned golfing holidays in Ireland, were among the first to opt out.

"Fear of flying, particularly transatlantic," is the main factor, said Mr John Power, chief executive of the Irish Hotels Federation.

The industry is now into a period of cancellations, he added. "Uncertainty is the main thing. Ensuring that air routes are kept open would be an objective."

The tourist season for North America - the US and Canada - typically runs from February/March to November, but a Bord Fβilte spokesman said a combination of foot-and-mouth disease, the downturn in Western economies and the atrocities last week means that the projected growth of 5 per cent in revenues and visitor numbers will not be met. This is the first time in 15 years that targets have not been met, he said.

The industry believes that it is too early to say what the impact of last week's events will be, but nobody is being optimistic.

Mr Brendan Leahy, chief executive of the Irish Tourist Industry Confederation, said: "By and large the signals are very, very serious in terms of the reduction in routes and activity and that is linked to a serious reduction in air travel. Americans are very valuable in that they come all year round and numbers could be quite strong to the end of November, so it's hitting us at a bad time."

On the outward side, travel agents already were feeling the impact of the reduction in corporate travel, according to Mr Fergus Kilkelly, president of the Irish Travel Agents Association. The association is "monitoring the situation" on skiing holidays in the United States and he predicted that there may be special offers to entice people to travel generally.