Travel disruption caused by the volcanic ash cloud has hit London's hotels.
Properties saw a 2.5% drop in gross operating profit per available room in April, according to the latest HotStats survey by TRI Hospitality Consulting.
The fall follows five months of consecutive growth.
The hotel analysts also said that revPAR (revenue per available room) in the UK capital fell for the first time since last October.
During the month, TRI said average room rates rose by 5.1% to £113.17 pushed up by a rise in leisure and rack rated business.
But occupancy dropped by 4.2% to 76.1%.
This was the biggest decline in occupancy in London since January, 2009.
Jonathan Langston, TRI's managing director, said: "Performance levels in London have been exceptional since the beginning of the year and it was always going to take something out of this world to slow their progress."
He warned that, with forecasts that eruptions from the Icelandic volcano Eyjafjallajoekull could have a long term impact, London hoteliers could face further setbacks.
The travel disruption has less impact in the UK regions with TRI reporting occupancy "relatively stable" at 67%.
But some cities, including Liverpool, Birmingham and Leeds, saw a decline in average room rates.
"Although provincial hoteliers are successfully increasing year-on-year room occupancy levels following the significant declines during the same period in 2009, market forces are dictating that rooms are being sold at a much lower price," Langston said.
But hotels around London Heathrow Airport benefitted from the travel disruption and reported a 5.7% increase in occupancy to 75.1% compared with April 2009.
www.trihc.com