The Clinton administration notified the British government Wednesday that it was revoking all pending licenses for the export of American firearms to British companies, American officials said.

The revocation is the first step in a plan to halt the sale of firearms by American companies to all 15 members of the European Union. Licenses to export firearms will not be issued for European Union countries until the governments have adopted laws to guarantee that the weapons are not re-exported "to the bad guys," as one senior official in Washington put it.In recent years, American firearms sold to European companies have ended up in the hands of terrorists and organized criminal gangs and in war zones like the former Yugoslavia, Turkey and Central Africa, according to American and European law-enforcement officials.

The administration's actions are part of a growing concern about the easy movement across borders of light weapons, which include handguns, automatic rifles, grenade launchers and hand-held missile launchers.

Here in Vienna this week, delegates to the annual meeting of the U.N. Commission on Crime Prevention and Criminal Justice are expected to call for a binding international instrument to curb weapons trafficking.

Washington has acted first against Britain, not necessarily because it was guilty of the most serious abuses, American officials said, but because the problem there was presented in the starkest terms.