LUANDA, ANGOLA -- The Marxist government here is haunted by memories of past bloodletting as it plans to convert to multi-party democracy and to allow free elections.

Earlier this month, the ruling Popular Movement for the Liberation of Angola-Workers' Party concluded its third congress since independence by formally approving a multi-party, democratic socialist system and accepting free elections in principle. A year-long constitutional revision process is to begin after a cease-fire is reached in Angola's civil war. No date was set for elections.

Unlike Mozambique, another former Portuguese colony and Marxist state undergoing a transformation to a multi-party system, there is little sign that Angola's leadership has much confidence in the process, or in itself.

Senior party officials displayed a noticeable lack of enthusiasm and considerable nervousness at the prospect of contending for votes with the U.S.-backed, rebel National Union for the Total Independence of Angola, which has fought to overthrow the Soviet-backed Luanda government for 15 years.

They loathe and fear rebel leader Jonas Savimbi, whom they blame for thousands of deaths and for massive destruction throughout the country. But they also view him as a formidable, charismatic opponent.

"I don't know how UNITA representatives will appear before you one day to ask for your votes when we all know that they infiltrate into our midst, armed and in the still of night, to attack you, kill and kidnap your children and steal your few goods," President Jose Eduardo dos Santos said at a Dec. 10 rally of MPLA supporters here.

Just what violence, either against the MPLA or within it, may be set off by multi-party democracy is one of the great unknowns of the pending transition here.

One of the memories that haunts senior party officials as they contemplate the future is the 1974-75 transition to independence from Portuguese colonial rule. The MPLA, UNITA and a third group, the National Front for the Independence of Angola, were supposed to share power and merge their guerrilla forces. Instead, a bloody, three-way power struggle erupted that led to the civil war.

"They are trying to avoid what happened in 1975 -- five armies and 25 parties," Methodist Bishop Emilio Julio Miguel de Carvalho said with some hyperbole.

Another nightmare haunting party leaders, worried about reactions of hard-line Marxists to the changes approved at the congress, is the 1977 coup attempt crushed only with the help of Cuban tanks.

Carvalho ascribes the fears of party leaders partly to the weight of African tradition and to the way democracy is coming to Angola. "A multi-party system is not an African system. It's only been tested negatively in Africa," he said in an interview. "You don't have two tribal chiefs in Africa."

Also, he added, "much of what is happening here is an imposition from the outside."

Dos Santos admitted in his opening speech to the congress that changes taking place in the international arena did not give Angola much choice. His speech was laced with references to the new spirit of U.S.-Soviet cooperation, the collapse of socialist governments in Eastern Europe and the wave of Western-style democracy sweeping the world.

To insist any longer on Marxist-Leninist ideology as a guide to development "in these changing times," he said, "would be like rowing against the tide."

At a public rally after the congress, the Angolan leader began explaining the massive changes that lie ahead for the MPLA in a multi-party system. He pointed out that the army, an inextricable part of the MPLA since it began as a rebel force, will have to disengage from politics as a "national" rather than a "party" force.

Not only will the MPLA have to get out of the army, it will have to loosen its hold over the state after 15 years of controlling everything the government thinks, plans, does and says, he said.

There was little indication during the congress that senior MPLA officials have fully digested what these changes will mean for the country, their party and possibly their own careers. Instead, their immediate concern appeared to be whether the MPLA would hold together through the rough political ride that lies ahead.

As the congress began, oldtime Marxists such as Lucio Lara and Maria Mambo Cafe, as well as ambitious reformists such as Foreign Minister Pedro de Castro Van-Dunem, were reported to be on the verge of leaving the MPLA to form their own parties.

Dos Santos, showing himself to be a far shrewder politician than many imagined, managed to convince both the Marxists and reformists not to abandon ship, while at the same time promoting pragmatists to the MPLA's Central Committee and Politburo.

Elections for a new 90-member Central Committee saw just over half of the old members dropped and younger, less ideological and more technically proficient party faithful brought in.

Dos Santos has put together an enlarged, 21-member Politburo. He kept ideologues Mambo Cafe and Roberto Antonio de Almeida but also included reformist Lopo Fortunato Ferreira do Nascimento, the leading "new thinker" of the MPLA, who also was elected to the Central Committee. Van-Dunem is now only a candidate member but remains foreign minister.

Political observers are asking whether the new Politburo, comprised of much of the same old guard of the former Marxist-Leninist MPLA, would be capable of espousing with any sincerity the "new thinking" of the party -- free enterprise, freedom of the press and Western democratic ideals -- or of adapting to the free-play politics of a multi-party system.