Hotels in continental Europe could face a drop in visitors in the last months of the year because of the strength of the Euro.
The warning came from Alex Kyriakidis, global managing partner of tourism, hospitality and leisure at consultants Deloitte.
He said: "The strength of some currencies against the US dollar, notably the Euro, is presenting a challenge for the hotel industry, particularly in Europe which is likely to see a downturn in visitor numbers from the US and UK during the remainder of the year."
The consultants said the global hotel industry made a "good start" to 2008.
All areas, except North America, enjoyed double digit growth in revenue per available room (revPAR).
In Europe, revPAR in the six months to the end of June rose to $115, a 15.2% increase on the same period in 2007.
The report said that despite the economic slowdown and the strength of the Euro, "a number" of European cities showed "strong growth" in the six months.
Hotels in Russia had some of the highest revPAR increases in Europe with Moscow up 25.1% to $269 and St. Petersburg up 37.1%.
Central and South Americas had the highest revPAr increases of 23%.
Those in the Middle East grew by 21.65, in Asia by 13.3% and in North America by 4.8%.
Mr Kyriakidis said: "Most regions have seen strong growth for the first six months of 2008, which is a great result for the industry given the current economic uncertainties facing the global economy."
Rail bookings up as fuel costs rise – Amadeus
IT travel company Amadeus said rail bookings among UK business travel agents have risen because of the cost of fuel.
Research by the GDS found that 58% of business agents had made more rail bookings in the first half of 2008 compared with the same period last year.
Just over half the agents (51%0 said that the cost of fuel had hit the number of air bookings this year.
But 61% said they had made more bookings this year than last. 30% said they expected the level of bookings to remain the same for the next six months.
But 58% predicted that their bookings would rise by 5%-10%.
While air bookings were being affected by oil prices, 63% of business travel agents said there was "minimal" affect on demand for domestic flights while 57% said demand for European flights was unchanged.