Brussels — For the first time in more than a decade, NATO is searching to replace its top official, Joseph Luns. A number of prominent European political figures such as former West German Chancellor Helmut Schmidt and Britain's ex-foreign minister, Lord Carrington, have been cited as possible successors.
Mr. Luns has held the post of NATO secretary general for 12 years, and has succesfully resisted previous efforts to replace him. This time, however, aides say he has let it be known that he would like to step down in late 1983 or next year, after he has seen the start of the controversial deployment of United States cruise and Pershing II missiles. The deployment issue has been perhaps the biggest challenge of his tenure in office.
The tall, gravel-voiced, jocular Luns was Dutch foreign minister for many years before taking over the leadership of NATO's civilian and political wing. He has held the post longer than any of his predecessors.
In this role as leading spokesman for the North Atlantic Treaty Alliance (NATO), Luns has been staunchly pro-American and sometimes critical of the ambivalence and pacifist tendencies in smaller European NATO countries, such as his own home state.
Such positions have sometimes made Luns a controversial figure within the alliance as well a target for Warsaw Pact attacks. Once a Dutch defense minister threatened to ''kick him over the goal line,'' and West Germany's ex-defense minister, Hans E. Apel, also sought Luns' ouster.
The post of NATO secretary general, as opposed to the one of allied military commander which is always in the hands of an American, is always filled by a European. His predecessors over the last 30 years have been Lord Ismay of Britain, Paul-Henri Spaak of Belgium, Dirk Stikker of Holland, and Manlio Brosio of Italy.
Though West Germany's Helmut Schmidt is mentioned prominently as a candidate, he is considered by many to be too powerful and independent-minded for the job.
A more likely successor than either Schmidt or Britain's Lord Carrington, however, is someone from the ranks of lesser-known small-country candidates.
These include three Belgians and one Luxembourger. They are current Belgian Foreign Minister Leo Tindemans; his predecessor, Henri Simonet; the current Belgian member of the European Common Market Executive Commission, Etienne Davignon;and the president of the EC Commission Gaston Thorn, who was formerly Luxembourg's prime minister and foreign minister.
The succession may come at the next NATO ministerial meeting scheduled for December.