Yugoslavia today took a symbolic step away from Marshal Tito's charismatic and highly personal style of leadership with the election of its first president with a one-year mandate.

The new head of state is Cvijetin Mijatovic, 67, the Bosnian representative on the collective presidency and a former ambassador to Moscow. But his powers are strictly limited and there is little chance he will acquire the kind of undisputed authority enjoyed by the late president Tito.

In an acceptance speech, Mijatovic pledged to do everything in his power to pursue Tito's policies of independence and nonalignment, which made Yugoslavia the first communist country to break away from the Soviet Bloc.

Through a quirk in the constitution, Mijatovic is Yugoslavia's third president in less than two weeks -- in contrast to three decades during which Tito held the office continuously. On Tito's death, the duties of head of state passed briefly to vice president Iazar Kilishevski, but his term of office expired today.

Foreign analysts interpreted the appointment of Mijatovic, a respected if lackluster politician, as a striking demonstration of how the country's new system of collective leadership will work. Rule by a charismatic individual is being dismantled in favor of rule by impersonal institutions.

During his 35 years in power. Tito refused to nominate a single successor. Instead, in an attempt to prevent deeply ingrained national suspicions from reemerging after his death, he set up an eight-man collective presidency composed of one representative of each of Yugoslavia's six republics and two autonomous regions.

Under the system, the presidential post rotates annually in mid-May among the collective leadership.

Tito's failure to designate a successor caused some concern both in Yugoslavia and abroad that a possible power vacuum might develop after his death. But he strongly defended the principle of collective leadership, with its intricate network of checks and balances, as the only way of avoiding a damaging power struggle between unscrupulous individuals.

Mijatovic's new duties include acting as commander-in-chief of the armed forces and representing Yugoslavia to the outside world. It is likely that one of his first major tasks will be to play host to President Carter who, according to Yugoslav and U.S. officials, will probably pay a brief visit to Belgrade next month following an economic summit in Venice.

In practice, however, real political power in post-Tito Yugoslavia appeared to be concentrated in a handful of senior Communist Party officials. Key figures include the Croat leader Vladimir Bakaric, who is himself a member of the state presidency, Defense Minister Nikola Ljubicic, and the former foreign minister, Milos Minic.

How long collective leadership can last in a country that has become so accustomed to one-man rule is open to question.

Many political observers here see it essentially as a convenient transition mechanism designed to allow the possible candidates for the succession to build up support. But this, analysts believe, could take two or three years.

At a ceremony marking Mijatovic's election, Kolishevski, the outgoing president served for only 11 days, said collective leadership had proved its ability to function effectively during Tito's four-month-long illness when it was, in effect, running the country.

The new vice president, Sugej Krajher, 66, is the Slovenian representative in the collective leadership. He is considered a pragmatic politician, chiefly concerned with economic affairs. Under the rules of rotation he will succeed Mijatovic as president next year.

A Serb by nationality, Mijatovic is credited by some Belgrade gossips with a minor role in the purging of the former secret police chief, Alexander Rankovic, in 1966.

Shortly before his fall, Rankovic visited the Soviet Union where he was hailed as "Tito's successor" by Soviet leaders impressed with his hard-line views. It is rumored that Mijatovic, then serving as Yugoslav ambassador to Moscow, reported the incident back to Tito.

In recent years, Mijatovic has held a string of important posts, but has done little to draw attention to himself. His wife, Mira Stupica, is one of the country's best-known actresses.