BELGRADE, Yugoslavia (AP) _ Serbia's government under President Slobodan Milosevic is trying to use its majority in parliament to take control of Belgrade's oldest newspaper and the accompanying media conglomerate.

The government says it is only trying to end the hazy ownership status that Politika and its publishing house have had for years.

But opponents call the move yet another Milosevic effort ensure absolute control of the media - and are threatening to take to the streets in protest.

''We want to transform the economic status of Politika. It is a publishing house of the greatest national interest, and we want to protect its assets and to improve them,'' Milivoje Pavlovic, Serbia's Information Minister, told The Associated Press.

The republic's parliament, dominated by Milosevic's Socialist Party, was expected to vote today on the proposal.

Founded in 1904 by a group of shareholders, the paper was ''socialized'' under the Communists after World War II. Rather than being state-owned, Yugoslav companies were largely self-managed by employees.

In the post-Communist era, it has never been clear who owned Politika.

Parliamentary approval of the proposal would give the government complete control over the Politika publishing house, which puts out 16 newspapers and magazines and runs a radio and a TV station.

During two days of debate last week, the opposition blocked voting on the motion by filibuster. The Socialists hold 197 of the 250 seats in parliament.

In addition to seeking control of the Politika publishing house, the government has threatened to ban Belgrade's independent B92 radio station and has refused to allow the capital's NTV television station, which is considered close to the opposition, to broadcast to all of Serbia.

Vuk Draskovic, leader of Serbia's largest opposition party, says that if government efforts ''to muzzle'' other media continue, the opposition will organize much larger demonstrations than those attended by up to 100,000 people last month.

After World War II, Serbia's media came under direct political control of the ruling Communists. But Politika managed to remain relatively independent and was considered one of the most liberal newspapers in eastern Europe.

After Milosevic came to power in 1987, Politika became a virtual government mouthpiece.

Opposition parties claimed Politika's biased reporting was largely responsible for the Socialist victory in Serbia's first multiparty elections, held in December 1990.

But in recent weeks, the publishing house replaced the editors of its two main dailies, Politika and Politika Ekspress. Their coverage of politics in Serbia, where new parliamentary and presidential elections are tentatively scheduled for November, has become far more objective. ''If (Milosevic's) commissars ever try to enter Politika, the opposition will boycott the coming elections,'' Draskovic said.

The Serbian Orthodox Church, the Writers' Association and other influential institutions that have recently criticized Milosevic's leadership have lent support to Politika.

Opposition to the takeover also has come from the new government of Yugoslavia, the two-republic federation dominated by Serbia.

Premier Milan Panic, a Belgrade-born California businessman with U.S. citizenship, and several of his ministers have all affirmed their support of free and privately-owned media.

In its own efforts to clarify ownership, Politika recently decided to become a share-holding company, with 10 percent of stock to be sold to employees and the rest issued as a public offering.