Argentina's 1980 winner of the Nobel Peace Prize, Adolfo Perez Esquivel, now on the 11th day of a protest fast, led about 25,000 people through downtown Buenos Aires tonight in a protest march against the military government's recent "final report" on the fate of disappeared dissidents.

The march, winding its way up the city's broad Avenida de Mayo to the Congressional Palace, closed since the military overthrew the civilian government in 1976, was the largest human rights demonstration here ever.

Perez Esquivel, four other hunger protesters, three Catholic bishops and representatives from nearly every important political and labor group were at the head of the march.

In a dramatic address to the crowd, Perez Esquivel said, "The only subversives in this country are those in the regime." He called the Army "an occupation force . . . They want to legalize the impunity of those who tortured and kidnaped at will."

"It's going to end, the military dictatorship is going to end," the demonstrators sang. "Sons of bitches," they shouted at Argentine security forces patrolling the protest.

Many marchers carried placards protesting the recent abduction and death of a well-known Peronist party activist and another man. Police say Osvaldo Cambiaso, the Peronist, and Eduardo Pereira Rossi were killed Saturday in a shoot-out with law enforcement officers in Buenos Aires province.

Human rights groups and civilian politicians said the two were abducted Saturday from a bar in Rosario, 240 miles west of here, by a group of men they said were government security agents.

Police have said Pereira was a leader of the once powerful Montonero organization, a principal adversary of the military government during the 1970s conflict the military refer to as the "dirty war."

The killings of Cambiaso and Pereira have caused a huge outcry from civilian politicians, human rights leaders, churchmen and labor leaders. The killings also have provoked criticism within the ranks of the armed forces, especially the Air Force, which sees itself being dragged down by association with blunders committed by the other services.

Tonight's march, which was supported by previously noncommittal rightist politicians and Peronist leaders, was originally called to protest the regime's so-called "final report" released April 28, in which the military absolved itself of responsibility in the disappearances and presumed deaths of thousands of people in the antiguerrilla struggle. No incidents or arrests were reported, and the march broke up peacefully.

Local and international groups say that between 6,000 and 15,000 people vanished during the military campaign against guerrillas and other dissenters. At least two of the missing are Americans, U.S. officials said this week.