Citing the soaring price of jet fuel, several foreign airlines began raising passenger fares or adding fuel surcharges.
Swiss International Air Lines last week increased fares 3% for flights originating in Switzerland.
For other flights, the increases will vary "depending on similar measures taken by competing airlines," the company said.
Air France, Austrian Airlines Group, British Airways, Qantas and Singapore Airlines also announced surcharges on various routes.
Several times this year, U.S. airlines tried and failed to increase fares up to $10 per round trip across the board, although some maintain the higher fares on routes where competitors adopted increases.
In other airline news:
* American and Mexicana airlines have begun code-sharing on each other's flights between the U.S. and Mexico and offering a reciprocal frequent-flier arrangement.
* Alaska Airlines on June 7 will start the only daily nonstop service between LAX and Ronald Reagan Washington National Airport. Introductory round-trip fares, for travel through June 30, start at $178.
* Singapore Airlines on June 28 will begin daily nonstops between Newark (N.J.) International Airport and Singapore. The carrier said the 18-hour, 9,000-nautical-mile flight would break the previous record, which it set Feb. 3 on its LAX-Singapore service, for the world's longest nonstop commercial flight. The LAX flights are nearly 8,000 nautical miles.
* Air-India will begin thrice-weekly direct flights, with a brief stopover in Frankfurt, Germany but no change of planes, on June 11 between LAX and Mumbai (Bombay), India. Round-trip coach fares vary; for June, they begin at $1,720. For details, visit www.airindia.com.