Passengers and travel agents have voted Singapore Airlines as this year's best international carrier in a Zagat survey that also showed how the economic downturn had grounded the travel industry.

The 2009 Airline Survey by the travel and entertainment guide covered 73 international airlines and 16 domestic U.S. carriers, rating premium and economy classes on a 30-point scale covering factors such as comfort, food, in-flight entertainment and luggage policies.

Singapore Airlines, the flag carrier of the Southeast Asian nation and which regularly wins passenger choice awards, scored top marks for its service in both classes.

Hong Kong's Cathay Pacific tied with Dubai's Emirates for the 2nd slot in the premium-class category while Emirates also scored second-best for its economy class service.

Virgin Atlantic and Air New Zealand were voted as having the third best premium class service and there was a three-way tie for the third ranking in economy class between Japan's All Nippon Airways (ANA), Air New Zealand and Thai Airways.

Among the U.S. airlines, Continental got the best score -- a 15 -- which Tim Zagat, CEO of Zagat Survey, said was an achievement despite lagging behind the others.

"The newer airlines continue to do well in the survey. Being less expensive to operate, they can therefore afford to provide better service," Zagat said in a statement.

"That airlines like Singapore, Emirates and Cathay Pacific do so well is a no-brainer - government support. The big question is how Continental does so well without any special advantages."

Continental was also named the best value carrier for international routes.

The survey, conducted online (www.zagat.com), polled 5,895 frequent fliers and travel professionals who collectively took 97,600 flights in the past year.

It was the third annual airline survey by the travel, food and entertainment guide, and perhaps unsurprisingly showed a decline in the number of flights people took this year due to the global financial crisis.

A third of overall respondents said they were flying less this year, while only 7 percent said they were flying more.

The proportion of flights for business declined to 61 percent this year from 64 percent in 2007 while leisure flights were slightly higher at 39 percent from 35 percent two years ago.