During his 35 years in power, President Tito toyed several times with the idea of appointing a successor. But, one by one, the possible candidates either died or disappointed him and he finally settled on the idea of a collective leadership made up of representatives of the many different Yugoslav nationalities.

What finally convinced Tito was the death last year of his close friend, Edvard Kardelj, the Slovene ideologist whose conciliatory qualities would undoubtedly have made him the most acceptable successor.

Ironically, it was Kardelj -- realizing that he was dying from cancer -- who advocated a collective leadership. In a speech shortly before his death, he denounced "little Titos" whom he accused of trying to push themselves forward as candidates for the succession when they possessed none of Tito's unique qualities.

How long collective leadership can last in a country that has been used to one-man rule for so long is open to question. Already, some senior Yugoslav politicians have been speculating about a new undisputed leader emerging even if he does not have Tito's charisma. They also agree that, within the top leadership bodies, some personalities wield more influence than others.

The Croatian leader, Vladimir Bakaric, stands out by virtue of his seniority and political acumen. Other important figures for the post-Tito transition include:

Milos Minic, 65, a Serb, foreign minister from 1972 to 1978 and now Yugoslavia's chief foreign policy strategist. Minic was frequently entrusted by Tito with delicate missions to Moscow and is the man chiefly responsible for devising a long-term strategy for relations with the Soviet Union.

He is a member of the party Presidium and president of the Council for Foreign Relations. A small, white-haired man with tired, kindly eyes, Minic has been described as "the Yugoslav Buster Keaton" because of his poker face. Some of his former colleagues have questioned his resolve, but during the last few years he emerged as one of the Yugoslav leaders determined to take a tough line with Soviets.

He has warned of Soviet-inspired attempts to split the nonaligned movement and, since Tito fell ill, has spoken out strongly against the Soviet invasion of Afghanistan. He first won international renown after World War II as chief state prosecutor at the trial of the anticommunist guerrilla leader, Draza Mihajlovic, who was executed in 1946. Minic has a history of bad health and heart disease.

Stane Dolanc, 54, a Slovene, member of the party presidium in charge of ideology.Blunt, efficient, and sharp-witted, Dolanc is the Yugoslav politician whose style is closest to Tito's. He was appointed party secretary in 1972 with the task of restoring order and discipline following nationalist and liberal upheavals.He performed the task well, but his rapid rise caused resentment and he was forced to resign as secretary last year.

A pragmatist by nature, Dolanc favors economic reforms including a possible extension of private enterprise. However, he backs a strong regional power base and his ruthlessness may make him unacceptable as an overall Yugoslav leader. Despite being overweight, Dolanc has won a reputation for energy and political dynamism -- a rare quality among Yugoslav politicians. He served as a political worker in the Army for 15 years and owed his initial advancement to Kardelj's patronage.

Nikola Ljubicic, 63, minister of defense since 1967 and member of the 23-man Communist Party presidium. An Army general, Ljubicic is the longest-serving government minister and was exempted by Tito from a rule limiting ministers to two four-year terms in office. His importance derives chiefly from his position since Tito referred to the Army's responsibility for keeping Yugoslavia united if serious internal strains develop after Tito's death.

With Ljubicic as its leader, the Army is likely to exercise a restraining influence on the would-be reformers but would only intervene in day-to-day politics in the event of a major crisis. Ljubicic appears to be a very efficient, if rather colorless, administrator. He commanded Tito's personal platoon of guards during World War II and had enjoyed Tito's total confidence since then. He is due to retire from his present post at the age of 65.

Branko Mikulic, 51, a Croat from Bosnia, member of the party Presidium in charge of cadres. As party chief in Bosnia, Mikulic was identified with the conservative wing of Yugoslav politics. He spoke out strongly against nationalism and demanded stiff sentences for "state enemies." Since his transfer to federal politics, he has sought to project a more liberal image, during Tito's illness, Mikulic attacked Stalinist ideas and demanded "democratization" of Yugoslav life. A capable administrator, he was chosen by Tito to fill the new post of chairman of the party Presidium in 1978. The efficiency with which he carried out the one-year mandate strengthened his position, but in view of his past reputation, it is doubtful that he could be acceptable as an overall Yugoslav leader.

Lazar Kolisevski, 66, Macedonian, former vice president and now president of the state presidency. As nominal head of state, Kolisevski is playing an important symbolic role in Yugoslavia's first change of power in 35 years. His mandate expires in May, when he is due to be succeeded by Cvijetin Mijatovic from Bosnia. But it is speculated that his term might be extended to provide continuity.

An old-style partisan, Kolisevski's political career seemed finished in the 1970s, but he was brought back following the crackdown on liberalism and nationalism. Always committed to the idea of a separate Macedonian nation, he was arrested during the Bulgarian occupation of Yugoslav Macedonia in World War II. He then spent 15 months in a Bulgarian prison awaiting execution before the war ended.

Veselin Djuranovic, 54, Montenegrin, prime minister since 1977. A former party chief in Montenegro, Djuranovic is identified with the cause of economic stabilization. The premier's job is not as important in Yugoslavia as some other European countries, but it demands patient negotiating skills in persuading different interest groups to agree on a common economic policy.