Federal authorities should expand tough new anti-terrorism measures to cover foreign air carriers with landing rights in the United States.

Sen. Lloyd Bentsen, D-Texas, said in a letter to Transportation Secretary Samuel K. Skinner released Saturday he was "dismayed" that emergency security precautions taken after the bombing of Pan Am Flight 103 apply only to domestic carriers with international flights."I do not think it requires a quantum leap in logic to conclude that as it becomes more difficult to penetrate the security of U.S. flag carriers because of their superior security systems, the terrorist threat may well shift to foreign air carriers which carry a large number of American passengers," Bentsen said.

About half of Americans traveling abroad fly on foreign carriers.

"If the primary basis for the emergency rulemaking is to minimize terrorism aimed at Americans particularly and the international traveling public generally, then I do not see how it is accomplished by a blanket exemption to foreign air carriers to the requirement for improved security operations," Bentsen said.

The Federal Aviation Administration in late December announced tightened security procedures by U.S. air carriers at 103 airports in the Middle East and Western Europe, including X-ray or physical inspection of all checked baggage and random physical checks of some carry-on baggage.

The added measures were prompted by the bombing of Flight 103 over Scotland, which 270 persons dead.

Bentsen said the measures did not go far enough. "The problem is that they (FAA) offered a half a loaf and half a loaf is just not good enough when you're talking about terrorism," he said.

Bentsen said he was urging Skinner to have the FAA coordinate its activities with the intelligence community in tracking terrorist activity and guarding against sabotage.

Skinner will head a U.S. delegation to a special session of the Council of the International Civil Aviaton Organization this week in Montreal, where protecting aviation from terrorists will be discussed.

The Transportation Department said the meeting's primary purpose will be to improve the council's international standards on passengers, baggage and cargo security related to sabotage.