The protest plan began to circulate, slowly and by cautious word of mouth, a few days before the ninth anniversary of Chile's military government on Sept. 11.

At 10 o'clock on the night before Gen. Augusto Pinochet's now-traditional celebration and national address, it was said, Chileans were to plug in all of their electrical appliances and bang empty pots and pans. The result would be a power overload, blacking out greater Santiago amid a clanging din of opposition to military rule.

Whether the protest call was widely disseminated could not be determined, but nothing happened. There was no blackout and very little noise in Santiago on the eve of the coup's anniversary, and the next day's official ceremonies passed with only a hint of popular opposition to Pinochet's long reign.

The failure of the gesture -- for which no one claimed responsibility -- was hardly an accurate measure of support for either the government or its civilian opposition. But the plan's very timidity, and the lack of any other public display on Chile's most emotional political anniversary, indicated the continuing weakness of organized opposition to one of the region's most hard-line military governments.

"The problem here is coming up with a viable mechanism" to coalesce an opposition movement, a labor leader said. "For those who have wanted change, all they have received is repression."

Although a deep recession and its accompanying high unemployment are believed to have sharply increased popular unrest in recent months, the political parties, labor unions and social movements opposed to military rule have had little success in expanding their activities or even making their platforms known in the country's tightly restricted political climate, opposition leaders concede.

Scattered protests have continued in the main universities, and two demonstrations in recent months have attracted 1,000 or more persons to downtown Santiago after being secretly organized by political movements -- all of which officially are banned. The parties continue to operate only under cover. Labor unions remain divided and relatively weak, and large strikes are rare.

Even human rights organizations and church-based social movements, which operate openly, are reluctant to organize large meetings or coordinate their activities. "Anything that could be interpreted as organizing or coordinating opposition is dangerous for us," said one rights activist. "We have to be very cautious."

Although armed groups opposing the government, such as the Revolutionary Leftist Movement (MIR in Spanish initials), have received some attention abroad, they appear to have little support within Chile and their activities attract only occasional notice.

Opposition leaders say the relative quiet on Chile's home front is a tribute in large part to the effectiveness of nine years of military rule, whose decrees and security police activity have succeeded in suppressing or splintering potential opponents.

While military governments in Argentina and Brazil have had to allow for growing levels of organized dissent, and Bolivia's Army has stepped out of power in favor of its civilian opponents, Pinochet has entered his 10th year of rule with few concessions in his authoritarian style.

Officials have moved to obtain the court-ordered expulsion of eight opposition critics, including four leaders of human rights groups and have banned a book and two radio programs that would have included moderate criticism of economic conditions.

Students organizing even nonpolitical campus groups have been arrested and charged that in some cases they had been tortured, and dissident labor leaders have been threatened with expulsion.

Rights groups estimate that as many as a million Chileans are now living outside the country, including an estimated 300,000 who left or were forced out for political reasons.

The result, say opposition members, has been erosion of dissident leadership ranks in the country and the intimidation of any who might join them.

"It is an effective tactic," said Jorge Osorio, a leader of the Justice and Peace rights group who is appealing a 541-day court-ordered expulsion for alleged illegal political activity. "Not everyone can afford to lose their job or their schooling to participate -- and the government has shown them that is what will happen."

Some Chilean officials and government supporters privately agree that repression against Pinochet's opponents remains harsh. But they argue that such tactics would not be politically feasible unless Pinochet were still supported by a majority here.

"There has been some dissatisfaction with the management of the economy," said Mario Arnello, a former congressman of the right-wing National Party who is a strong supporter of Pinochet. "But there is not a viable political alternative to the present government. And when there is not a political alternative, people are not going to engage in political agitation. Their priority is simply to solve the economic problems."

Opposition leaders deny that conclusion, but they acknowledge that the military government has always been supported by a significant, though minority, sector of the population.

"Two years ago, the government probably was supported by 40 percent of the population," said one Socialist Party leader, who like several others interviewed said he could not be quoted by name. "But now they have no more than 20 percent support."

Some opposition leaders and political analysts sympathetic to moderate political movements point out that Chile's opposition has been damaged by frequent feuding between rival groups and by the lack of consensus on how to oppose the government's policies or shorten Pinochet's military rule, now scheduled to last at least seven more years.

The Socialist Party of former president Salvador Allende, for example, is now divided into three main movements inside Chile, and supporters say a myriad of smaller factions can be counted both in the country and among exiles.

The party consequently has done little organizing as members debate whether resistance to Pinochet should be violent or nonviolent, or whether the Socialists should join in conciliatory fronts other parties have tried to organize.

"So much of the leadership is outside the country, and many of them don't understand the situation here anymore," complained one former activist. "They are still addressing the Chile of 1973, and the country has changed completely since then."

Some political leaders now envision negotiating with the Army for the formation of a multilateral national government to replace Pinochet. The ban on political activities would be ended under this plan, but political parties would agree to share power for the near future with the armed forces.

But this plan, argued by its supporters to be the only hope of returning to a form of democratic government in the near future, is rejected by other large sectors of the opposition--who say they continue to hope Pinochet will be brought down by some kind of popular uprising.

Most of the dissident activity has thus been isolated and projects to unite labor leaders or the several parties of the socialist left under one plan of action have stalled.

"In Chile, you cannot talk of a broad front or a united front, because there are always people who will not want to include the Communists," said Manuel Bustos, the leader of a union amalgam. Bustos' own group has been reduced to debating whether to send Pinochet a letter asking for his resignation or to propose a new government to the Army.

Either proposal, he admits, is likely to have little effect other than the possible arrest of its authors.