NEW YORK, FEB. 14 -- Pan American World Airways fired the latest salvo in the troubled air travel industry's fare battles today, and some big competitors were soon to follow with their own sales.

Pan Am said it was offering a variety of round-trip tickets, some to foreign destinations, for prices that are discounted in many cases by more than half.

American Airlines and Northwest Airlines immediately said they were matching the promotion with their own fare-slashing, although others said they were just studying the move for the time being.

"These are not going to be fares based on any possibility of a profit," Delta Air Lines spokesman Neil Monroe said.

But Pan Am, which is operating under Chapter 11 protection in U.S. Bankruptcy Court, said it was trying to stimulate business. Airlines have been hit hard by high fuel prices, the recession and a drop in bookings that came as passengers began fearing Iraqi-sponsored terrorism.

Pan Am said its cheap tickets would apply to most cities it serves in the continental United States and to many overseas destinations, including Western Europe. The tickets cost as little as $119 each way for passengers who fly a regular flight of at least $250 by March 1, or as little as $139 each way for passengers who do not fly other flights.

American and Northwest quickly matched the Pan Am promotion with deals they said were the same or better.

The travel is good from early April through May 20 on all three carriers.