LONDON – Fresh snow forecasts threatened to prolong chaos caused by a cold snap that could also dent German growth, and airlines and rail networks struggled to restore normal services in parts of Europe on Wednesday.

Disruptions to flights and high-speed train travel in continental Europe and Britain, have created travel chaos for tens of thousands of travelers in the busy Christmas period following heavy weekend snowfalls.

Cold weather was likely to clip fourth quarter growth in Germany, Europe`s biggest economy, Volker Treier, chief economist at Germany`s DIHK chamber of industry and commerce, told Reuters.

"A lot of construction projects have been stopped and a lot of business trips canceled," he said. "Freight transport has also had weather problems. The bottom line is the harsh weather will cost about a half a point of growth this quarter."

German railways put on more trains to help stranded air travelers reach their destinations but in France the national aviation authority asked airlines to reduce services as a precaution after more snow was forecast.

In Britain, the bad weather has caused severe delays to rail services across northern and central districts and forecasters said more heavy snow was on the way.

Travel havoc has triggered calls for legislation to force airports to deal more effectively with bad weather.

European Union transport chief Siim Kallas said he was considering forcing airports to provide a minimum level of infrastructure support during severe weather.

London`s Heathrow, the world`s busiest international airport, and Frankfurt Airport, the biggest on the continent, said on their websites that operations were returning to normal after severe disruptions.

Wolfgang Prock-Schauer, chief executive of Lufthansa`s BMI airline, accused Spanish-owned BAA of being unprepared for the heavy snow at Heathrow.

"What is really incredible is that 10 cm (4 ins) of snow closed the airport down for two days and then it operated at one-third capacity," he told the Times newspaper. "BAA was not prepared. It did not have enough de-icing fluid."