Violence-weary El Salvador has responded to its new civilian-military government with a mixture of relief and heavy skepticism.

There is a widespread feeling, as one local attorney said, that "this is our last chance to avoid an all-out civil war" promoted by right-and leftwing extremists who have spent the past several years trying to exterminate each other.

At the same time there is strong concern about whether the new government has the will or the power to change conditions that brought the country to the brink of disaster. Monday's overthrow of President Carlos Humberto Romero -- the last in an unbroken, decades-long line of rightist Army generals in the presidency -- may turn out to be the easiest task the new government will face.

One high-level member of the Catholic hierarchy, always harsh in its criticism of Romero, said "I know it's not very Christian, but I maintain a deep distrust of the military."

Still he said, 'it was the only way. We will wait and see what they do."

That a coup was in the making was an open secret in El Salvador. Last year, a clandestine group of Army officers calling itself Military Youth Council began circulating declarations charging the Romero government with corruption, violation of the constitution, and dirtying the name of the armed forces.

The call for Romero's ouster became more intense as terrorist kidnapings, assassinations and bombings increased from the left. Rightist security forces and government-sanctioned paramilitary groups answered in kind and became more repressive. Both foreign investment an domestic capital began fleeing the country.

With the July fall of Anastasio Somoza's government to leftists in Nicaragua and growing adhesion to appeals for insurrection among desperate peasant and labor groups, both Salvadoran moderates and the United States stepped in to try to avoid a radical takeover.

There was little acceptance of superficial reforms made by Romero under intense U.S. pressure, and little hope that upcoming elections under his government would be different than rigged contests in the past. Gradually, the temporary imposition of a "progressive" military-led government began to have more appeal.

Although the United States has denied involvement in the coup, informed sources here agree the likelihood that such an action would be mounted by the U.S.-allied Salvadoran military without implied U.S. approval is remote.

Adolfo Arnoldo Majano and Jaime Abdul Gutierrez, the two Army colonels who serve as figureheads for the young officers' group and took control after the coup, have outlined an ambitious program. It includes agrarian reform and the restructuring of a traditional economic system that had put the vast majority of the country's wealth and resources in the hands of a small oligarchy.

The colonels have called for political pluralism, early elections, and an end to deep-seated official corruption. They have promised a halt to harsh repression by El Salvador's security forces. Perhaps most importantly, the two colonels have formed a junta in which they are outnumbered by three civilians, painstakingly chosen as representative of civilian groups and personally "clean" in terms of association with the old power structure.

While the new inhabitants of the presidential palace have spent the past week busily trying to form a Cabinet that will divide power among a number of competing political groups and holding nervous press conferences in which sincerity and appeals for support have outweighed concrete initiatives -- business as usual has continued outside.

The Salvadoran Human Rights Commission said at least 100 persons were killed this week in confrontations with security forces.

Informed church and human rights sources this week charged that, although some top-level military commanders have been changed, middle-and lower-level officials -- active in the Romero government and in some cases, accused of human rights abuses -- have retained their jobs or even received promotions under the new government.

Today a Catholic radio station and a group of young Army officers in Santa Ana, El Salvador's second largest city, denounced the appointment of Col. Jose Guillermo Garcia as defense minister because of his association with Romero.

Roman Mayorga, one of the junta's civilians, echoes the military, blaming past abuses not on the Army but on El Salvador's ostensibly separate "security organizations." There are three such agencies, including the National Guard, the national police, and the finance police.

Junta statements thus far have implied the new government yet has exerted little control on the supposedly semiautonomous agencies.

The new government faces equally severe problems from the left.

The Popular Liberation Forces is the largest of three Marxist guerrilla groups. It was set up in 1970 and is composed of hard-core militants dedicated to the complete abolition of capitalism and the bourgeois classes through long-term armed struggle.

Allied with this group is the Popular Revolutionary Bloc. It recruits followers among blue-collar workers and in poverty-stricken rural areas, and it organizes protests ranging from marches to the occupation of factories and foreign embassies.

These two organizations -- along with the guerrillas of the Armed Forces of National Resistance -- have denounced the new junta. These groups see the promised reforms as a temporary setback for the revolutionary struggle.

A third guerrilla organization, the People's Revolutionary Army, and its mass-action organization known as the Popular Leagues-28, have the same long-term goals as the others. But, like the Sandinistas in Nicaragua, they believe temporary alliances can be made with the more "progressive elements" of the bourgeoise in order to achieve short-term goals.

In what the government considers the most positive sign so far, Popular Leagues-28 -- ostensibly also speaking for the People's Revolutionary Army -- said yesterday it would not oppose the junta, but that it would wait and see.