Hundreds of Kosovo Albanians, fired a decade ago in a Belgrade government purge, demanded their state jobs back today in spirited demonstrations that dramatized efforts by Kosovo's majority population to reassert its control over the Serbian province.

The demonstrations, which included a brief takeover of a radio station here in the provincial capital, indicate that even though the war in Kosovo may be over, a new battle -- for jobs and power -- is just beginning.

On one side of the dispute are thousands of Serbs still employed by state-run companies in Kosovo, including those that provide power, water, entertainment and other municipal services. Without those jobs, the Serbs say, there is little incentive for them to remain here.

On the other side are tens of thousands of ethnic Albanians who were fired from these jobs when the Serbian government stripped Kosovo of its local autonomy in 1989. They experienced a decade of forced idleness, surviving largely on remittances from relatives living overseas. With the war over and Serb-led Yugoslav security forces gone, the ethnic Albanians want their jobs back immediately and in recent days have attempted takeovers of a downtown hotel, the headquarters of the power company, a city hospital, a university and assorted restaurants and cafes.

The struggle has led NATO officials to try to cobble together temporary agreements between Serbs and ethnic Albanians in hopes of averting further violence. The United Nations, which is responsible for establishing a civilian Kosovo government, has barely opened its small office here, forcing NATO to step into the breach.

Already, most of the Serbs on the staff of the University of Pristina and the local hospital have fled the province, part of a migration of Serbian professionals that NATO and U.N. officials worry will permanently alter the ethnic makeup of Kosovo, whose population of 1.8 million before the war was 90 percent ethnic Albanian. A prominent Serbian surgeon is missing and feared kidnapped; a Serbian professor was killed last week amid warnings to other Serbs on the university faculty that they should resign.

At the city hall and the office building housing Kosovo's only radio and television stations, ethnic Albanians today signed statements demanding immediate reinstatement in their former jobs, then quietly pushed en masse toward their former offices. NATO troops barred their way at the city hall, but a group of former radio workers briefly took control of the radio studio.

Albanian folk music was broadcast on the station for the first time in years until NATO soldiers ordered the ethnic Albanians out. Talks between the station's Serbian manager and representatives of the ethnic Albanians are stalemated, as each side wants virtually all the estimated 1,000 jobs there.

Several blocks away, NATO officers made little headway in brokering a temporary arrangement for staffing Kosovo's electrical utility -- a huge enterprise at which 13,000 people once worked. Negotiations were recessed until Wednesday after five hours of talks.

Given the composition of the negotiating teams, there seems little doubt that compromise will be difficult. On the Serbian side, most of the participants are utility officials who were handpicked for their posts by the ruling Socialist Party in Belgrade, capital of both Yugoslavia and its dominant republic, Serbia. Ethnic Albanians charge that some of the Serbian negotiators have participated in or supported war crimes, and one man is said to have helped orchestrate the mass firings at city hall in 1989.

On the ethnic Albanian side, almost all the negotiators were selected or approved by leaders of a provisional government created by the Kosovo Liberation Army, the rebel group that fought for the past 16 months for Kosovo's independence. NATO officials here say they have little choice but to accept the KLA intervention because it has become virtually the sole ethnic Albanian political force in Kosovo.

Ibrahim Rugova, a moderate separatist politician and KLA rival who has twice been elected president of a Kosovo shadow government, is in Italy and has not visited Pristina since the war ended on June 10. His political organization is a shambles and has played no role in the effort to forge a new civilian structure here.

KLA political leader Hashim Thaqi, who serves as prime minister of the provisional government, has tried to calm those demanding immediate job reinstatement. In the town of Kosovska Mitrovica on Saturday, Thaqi stood on a U.N. vehicle and told a throng of several hundred angry hospital workers barred by Serbs from reaching their former workplace: "Please be patient. We are dealing with this situation. You will soon be able to move freely, and Kosovo will be one."

The crowd cheered Thaqi's remarks and dispersed after he described a deal worked out by NATO and U.N. officials with Serbian hospital administrators the previous night that would allow two ethnic Albanian doctors and a nurse to return to work. Further negotiations are to be held Tuesday on dozens of other jobs.

But NATO officials in Pristina say they suspect that Thaqi and Rustem "Remi" Mustafa, the KLA commander of the zone that includes Pristina, have been trying to influence the negotiations by helping organize some protests by ethnic Albanians in front of their former workplaces.

British Lt. Col. Jeff Neald, who is trying to mediate a jobs accord between the rival factions, said that Thaqi and other KLA officials "all have a role to play" in resolving the issue. But, Neald said, "we're not in the business of sacking Serb workers" and that for the moment his solution is to promise that all Serbian employees can stay and former ethnic Albanian employees can be rehired. The U.S. and British governments can pay the additional salaries until a more permanent solution can be reached, he said.

"I've been firefighting," Neald said. "You find me the U.N. administrators, and I'd be delighted to step aside."

For Martin Cuni and 18 other men seated on a hill near the radio station, the negotiations are just one more deferral of a decade-old quest to regain their jobs. Once head of the KLA's clandestine radio station, Cuni has been appointed by Thaqi's government to lead the efforts to reclaim radio and television jobs for ethnic Albanians by gaining ownership of the stations. He said that Serbs can be employed according to their percentage of the total population, now estimated at about 5 percent.

"Given the length of time these people have waited already, one can understand their impatience," said U.N. spokesman Kevin Kennedy. But he warned that those who take over public institutions through means not acceptable to the United Nations would not receive Western technical or financial assistance.

CAPTION: The first U.N. repatriation of Kosovo Albanian refugees from Macedonia took place yesterday -- a bus convoy carrying 335 people, including this infant.