Pan American World Airways said yesterday that it will attempt to recoup some of the European business lost because of Americans' fears of traveling abroad by initiating a highly visible security program.

In a contrasting approach to luring Americans back to Europe, British Airways said yesterday that on June 10 it will give away 5,200 seats to Britain from 15 U.S. cities as part of a $6 million promotional campaign.

The two dramatically different approaches represent the lack of agreement in the industry about what it will take to bring Americans back to Europe after what has been one of the worst financial quarters in history for the airlines, with losses exceeding $600 million.

International travel accounted for $8 billion in airline ticket sales last year, according to William Jackman, a spokesman for the Air Transport Association. And travel experts have said that American travel to some overseas locations could fall by as much as 80 percent this summer, the biggest season for international tourism.

"We thought we had to go on the offensive to try to stem the publicity that the few terrorist acts have had on travel and traffic to Europe," said Jeff Kriendler, a Pan Am spokesman.

Though not the only airline to increase its security measures, Pan Am was the first to go out of its way to alert travelers to its stepped-up screening of passengers, baggage and employes, taking out full-page advertisements in six major U.S. newspapers.

"It is a departure from usual airline marketing," said the spokesman. "But the nature of the industry and the environment has changed so dramatically that we have to change, too."

A spokesman for British Airways, on the other hand, downplayed concerns about terrorism, saying that the airline's promotion was "mainly to stimulate the market. . . . Pan Am's vision of the problem is up to them. We don't believe it's necessary to draw attention to security with a lot of hoopla. . . . We feel confident with the security we have."

"I think it's foolish for them to deny the association with terrorism," said the Pan Am spokesman.

Pan Am talked with travel agents and commercial travel representatives and learned that not only did travelers want security to be improved, but they wanted to be able to see that improvement, according to Kriendler.

"They want visible evidence, whether it's manpower, equipment or sniffer dogs," he said. "And they're not opposed to paying for it, nor would they be opposed to having their travel plans altered."

American Airlines last week began an increased security program, saying it was instituting procedures that the public can see in addition to behind-the-scenes steps, including hiring extra security personnel, requiring more information about ticketed passengers, X-raying all baggage and, in some instances, searching passengers.

Pan Am's new program, which will be partly paid for by a $5 surcharge on transatlantic tickets, will be called ALERT, and will begin on June 12.

Spokesmen for both Pan Am and American say that the new security measures will require that passengers for international destinations check in from 90 minutes to two hours ahead of departure times.

A spokesman for the Federal Aviation Administration, which sets minimum standards for airline security, said yesterday the agency welcomes anything that the airlines can do to increase passenger safety.

Industry analysts say that Pan Am and TWA have been the U.S. airlines hit hardest by the reduced traffic to Europe, because both airlines derive half or more of their total revenue from North Atlantic travel.

Pan Am, which already has laid off some of its reservations agents this year, could face further layoffs, the spokesman said.

That same business is crucial to British Airways, which yesterday announced separately that it had canceled the planned recruitment of 1,500 employes this summer and would drop some services this summer to cut losses.

A British Airways spokesman said yesterday that the state-owned company hopes to increase its market share by one or two points with its dramatic promotion, on which it will spend $3 million in promotion and $3 million for the cost of the seats.

The 5,200 flights to Britain on June 10, representing all the airlines seats on that day, will be given away in a drawing set for May 29. Entry forms will be available in 23 daily U.S. newspapers today, and also can be obtained from travel agents. Winners who already have booked flights to Britain on June 10 will get vouchers for free future travel, according to the spokesman.