Singapore Airlines said Wednesday it will suspend some international flights as the worsening global economy takes its toll on travel demand. Flights to India, Southeast Asia, the United States and Europe will be affected, SIA said in a statement.

The changes will be implemented progressively and will apply until the end of March.

Flights between Singapore and the Indian city of Hyderabad will be cut to three times weekly from four, the airline said.

Service between Singapore and New Delhi will be trimmed to five times a week from six, while Mumbai-Singapore service will be cut to four times a week from five.

In Southeast Asia, two flights between Singapore and Bangkok will be suspended from February 2, although the airline said it will continue to operate 25 flights a week to and from the Thai capital.

In Europe, two flights operating between Singapore and London will be suspended on Mondays and Thursdays from March 9-23. The frequency on the Singapore-London route will be cut to 19 flights a week from 21.

Services between Singapore and Zurich will be reduced from daily to five times a week, SIA said.

Earlier Wednesday, SIA said it was reducing its all-business class service to New York and Los Angeles in the face of the global economic downturn.

The 14 weekly Airbus A345 flights will be cut to 10, it said, adding the change will initially take effect between February 17 and March 25.

SIA said its December passenger numbers were down 7.5 per cent year-on-year.