The left-wing guerrillas holding the Dominican Republic Embassy released one of their 18 diplomatic hostages today and proposed a meeting in Panama with leaders of Columbia's establishment, including the president, to resolve the crisis.

Costa Rican Consul Rolando Blanco emerged smiling and in apparent good health from the embassy where he and the others have been held since Feb. 27.

The leader of April 19 Movement guerrillas, meanwhile, called for the meeting with President Julio Cesar Turbay Ayala to resolve the siege and reach a social compact to avoid armed revolution.

"The country has entered a period of institutional crisis, a period of great insecurity and violence," said Jaime Bateman, the M19 "maximum leader." He is not among the estimated 15 guerrillas still holding 17 diplomats, including U.S. Ambassador Diego Asencio, in the embassy here. Presumably he and others not holding the embassy would attend the session in Panama.

This "summit meeting" should take place May 1 in Panama. Bateman told journalist German Castro Caicedo, who was spirited away from his Bogota home Thursday for an interview in an undisclosed location. The guerrilla leader said the meeting should "discuss where the country is going and see if there are possibilities to prevent the war that most reactionary senators consider inevitable."

In the tape-recorded interview, Bateman reiterated the M19's hope that the embassy siege will be resolved "in a nonbloody and civilized" way. He expressed belief that a solution could be found within "half an hour" as such a meeting.

Castro was released outside a newspaper office after 36 hours. He then made known the M19 proposal, which came on the 10th anniversary of the allegedly fraudulent 1970 presidential elections from which the April 19 Movement takes its name.

After being questioned by the police, the journalist was flown to a rural military facility about 60 miles from Bogota where Turbay and his Cabinet are spending the weekend. Castro carried a private letter from the M19 to Turbay, the contents of which were not revealed.

The governmemt did not respond immediately to the M19 proposal, the first new idea for resolving the embassy crisis since talks between guerrillas there and government officials virtually collapsed earlier this week.

The talks, which appeared to be on the verge of success after the government privately said it would consider releasing some of the "political prisoners" demanded by the M19, foundered after the guerrillas demanded freedom for several top M19 leaders currently in jail. The government refused to release the seven -- although eight others were freed on a finding of no cause for prosecution.

At the embassy, the guerrillas said Blanco, the Costa Rican, would be the last hostage released until there is an overall settlement. About 40 hostages have been released since the takeover.

Bateman said detention of the hostages, among them 11 ambassadors, has focused both national and international attention on what he said was Columbia's "formal democracy." This includes elections and freedom of the press, the M19 leader said, but is increasingly circumscribed by repressive state of siege and national security statutes that he charged the government has used to detain, torture and force confessions from suspected guerrillas.

"The central theme now is whether democracy exists," Bateman said. "We are not saying, nor have we ever said, that there is a fascist dictatorship in Columbia. But we believe that the country is going toward it, toward . . . a dictatorship that maintains formal democracy but which also maintains a very special form of repression."

The M19 leader said that the charges of serious human rights abuses here have been confirmed by Amnesty International observers and the U.S. State Department's human rights report. This week, Amnesty issued a report that said Colombian police have systematically tortured and illegally detained hundreds of Colombians over the past year as part of a campaign to wipe out armed guerrillas such as the M19.

The government denied the allegations in the Amnesty report and invited the Inter-American Human Rights Commission here. Members were gathering in Bogota this weekend to begin their investigation Monday.

Bateman said the M19 would like to reach an accord with the government. In return for ending the state of siege and doing away with certain of the national security laws, he said the guerrillas would lay down their arms and work within the system to eradicate poverty and illiteracy.

The M19 said the proposed meeting in Panama should include, besides Turbay, three retired generals, three former presidents, leftist Colombian novelist Gabriel Garcia Marquez, several former foreign ministers, businessmen and politicians.

There was heightened security throughout Bogota today in anticipation of possible bombings, kidnappings or other incidents marking the 10th anniversary of the presidential election lost by former military dictator Gustavo Rojas Pinilla, a right-leaning populist who the M19 says was robbed of victory by fraud. The M19, founded in 1974, was itself a rightist group that has moved leftward over the years.

The M19 and other guerrilla groups have seized milk trucks and schools in poor sections of Bogota during the past several days, passing out free milk to school children and painting slogans on the schools' walls before escaping.