The Federal Aviation Administration will require airlines to conduct safety assessments of their foreign airline partners, but international law will not allow the FAA to do so directly, the government said today.

The decision formalizes a process already started by major airlines under pressure from the Defense Department, which pays millions of dollars a year to airlines for military and civilian travel.

The announcement, by Transportation Secretary Rodney E. Slater, came at a conference attended by aviation authorities from 93 countries, held in the same hotel where the 1944 "Chicago Convention" set up procedures for international airline travel that remain in effect today. The 1944 convention failed to open all the world's skies to commercial aviation but settled on a process of "bilateral," country-by-country treaties. The conference is an effort to begin moving beyond the bilateral treaties to a multilateral arrangement.

The FAA resisted any foreign airline assessments for years on the basis that its authority stopped at the water's edge, but pressure has been growing to take some action as aviation becomes more global.

Under "code sharing," a U.S. airline, for example, may sell tickets to an overseas destination with part of the flight on the U.S. airline and part on a foreign carrier. But the entire itinerary is under the U.S. carrier's name--or "code"--and a single flight number.

While the FAA can regulate the U.S. carrier, and the Defense Department can perform rigorous safety audits of U.S. airlines as a condition of government travel contracts, they cannot directly assess the safety of any foreign airline even if U.S. passengers are flying on a code-share ticket.

So far, there has been only one major code-share crash involving a foreign carrier--the 1998 crash of Swissair Flight 111 with about 50 Delta Air Lines passengers aboard. EgyptAir Flight 990 had more U.S. citizens aboard than any other nationality when it crashed Oct. 31 off the Massachusetts coast, but those tickets were sold directly by EgyptAir and not a U.S. partner.

Last month, in a report on the 1997 crash of a Korean Air jet on Guam, the National Transportation Safety Board said that the FAA did not do enough to assess the safety of foreign airlines flying to the United States, and it recommended greater scrutiny of the safety records of foreign carriers.

Slater and FAA Administrator Jane Garvey said any airline that fails a safety audit by a U.S. partner will automatically lose its code-share status, a serious economic blow to most foreign airlines. Likewise, any U.S. airline that fails to conduct periodic audits or to follow FAA audit guidelines will lose all code-share authority with all foreign airlines.

The FAA guidelines are not yet written, but Slater said the process already started by U.S. airlines is providing "significant insight" as to how an assessment program should work. The guidelines will establish qualifications and training of airline employees who conduct the audits, and specific operational areas to be audited.

The Transportation Department secretary must approve all code-share plans. Until now, the decision was made strictly on economic grounds. Slater said the economic decisions will still be made, but a negative safety-audit report on an airline now will automatically veto any code-share arrangement.

The audits must be conducted on new code shares and on existing agreements "periodically," at least every two years unless the final guidelines require more frequent inspection.

The audits will be considered proprietary and will not be released to the public, but Slater said the report from the FAA to the Transportation secretary will be public. Exactly how much detail will be included in the FAA report is unclear.

The FAA now assesses the aviation regulatory authorities of various countries, assigning them a rating of "1" if the pass, "2" if they need work but are trying and "3" if they fail. Slater said the country of origin of any airline must get a rating of 1 to have a code share approved.