The position of the Rev. Timothy S. Healy, president of Georgetown University, regarding a proposed speech on campus last March by Roberto D'Aubuisson of El Salvador was reported incorrectly yesterday. Healy approved the appearance, but the speech was canceled when the State Department denied D'Aubuisson a visa.

Roberto D'Aubuisson, the leader of El Salvador's extreme right wing, last night urged the Reagan administration to convert covert support for "contra" rebels in Nicaragua to an open program of aid.

Speaking at Georgetown University, D'Aubuisson said the administration "ought to make a decision clearly."

"Let them support the 'contras,' but let them do it openly. Let them define their position clearly," D'Aubuisson said in response to a question. "Let's not have another Bay of Pigs," he added in a reference to the U.S.-supported 1961 attempt by Cuban exiles to overthrow Fidel Castro.

Aiming his speech at "the youth of America" through the news media, D'Aubuisson said he was "totally innocent of all that I am accused of," referring to charges by U.S. officials that he is linked to death-squad activity in El Salvador. "I speak from my heart, my belief in God, my mother and my children," he said.

D'Aubuisson said he had been demanding for four years that his accusers offer proof of their charges and that it had never been produced.

The Rev. Timothy S. Healy, president of Georgetown University, called D'Aubuisson "a murderous thug" last March in refusing to allow the campus Young Americans for Freedom to invite D'Aubuisson to speak. Healy is "badly informed" about the situation, D'Aubuisson said last night.

He spoke on the third day of a four-day visit to the United States, during which he has met with several media organizations and received a plaque from more than a dozen conservative organizations honoring him for his efforts against communism in El Salvador.

D'Aubuisson, a former army major and unsuccessful presidential candidate of the ARENA party last March, delivered a kind of civics lecture to about 120 Georgetown students and faculty members. About 20 members of the audience stood and turned their backs as he began speaking.

Outside the auditorium, about 200 Georgetown students braved the rain to protest D'Aubuisson's appearance. They chanted "Asesino assassin D'Aubuisson" and called on the United States to get out of El Salvador.

In his remarks, D'Aubuisson said he was pleased to see the demonstrators because "if this were Cuba or Moscow, it would not be going on."

He told his audience to remember that Marxism "is not a revolution, it is only a conspiracy." He said El Salvador is key to preventing Soviet expansionism into the Caribbean, which is strategically important because of the oil of Venezuela and Mexico and because of the Panama Canal.

"The Caribbean should belong to us Americans, in the broad sense, and not to the Soviet Union," he said.

D'Aubuisson's visit to the campus sparked a controversy over tickets to the speech when YAF campus president Gerard Alexander said he was giving them out to ensure "a positive audience" for the appearance. Walter Cramer, assistant dean of student affairs, said it would have been against university policy to exclude anyone, but added he had received no complaints on the matter.

Some of the students protesting last night said the YAF purposely chose a small auditorium to limit the number of demonstrators.

"We're paying for this and we can't even get in to criticize him," said Miles Irish, a sophomore.

Alexander said he chose the auditorium for security reasons, and added that tickets were made available to various student groups.

D'Aubuisson spoke directly to the concerns of the demonstrators. "I only made one mistake in my campaign" for president, he said. "I told the truth . . . and I was no longer labeled the leader of a democratic party. I was a rightist.

"When I said the Caribbean was the goal of Soviet expansionism, then I was charged with being the leader of the death squads by the international press."

D'Aubuisson directly challenged Craig Pyes, the author of a controversial series of articles about the origins and functions of El Salvador's death squads that was published last year in the Albuquerque Journal and the Los Angeles Times. "I would like to meet him," D'Aubuisson said. "He had details of my life I don't even know myself."

During the question period that followed, Pyes, who was in the audience, responded to D'Aubuisson's assertion that they had never met. D'Aubuisson then admitted that they had, and said that Pyes had "become part of the conspiracy" against him because "he sneaked in among us as a friend; he lived it up with friends of ours in El Salvador, and for money he went to print his story. He's the one who says he has the proof. Let him show it and present it to a judge."

Pyes' articles, written with Laurie Becklund of the Los Angeles Times, caused a stir at the time of their publication for the detailed information the reporters said they had obtained from death-squad members. Pyes is now a reporter for the Committee for Investigative Reporting.