SAN SALVADOR, OCT. 28 -- The testimony of a U.S. military adviser, given to the FBI and then repudiated by him, suggests that the Salvadoran army chief of staff and other senior officers knew of a plan to kill six Jesuit priests well before their deaths last November.

The adviser, Army Maj. Eric W. Buckland, gave the testimony Jan. 11-12, then recanted it a week later, saying he felt confused and pressed by FBI agents who interviewed him. Under congressional pressure, the FBI recently submitted the testimony to a court here. His statements were released here last week.

U.S. judicial officials said the testimony was not submitted earlier because its repudiation made it useless in a legal proceeding. Nonetheless, Buckland's original statement raises questions about whether top-ranking Salvadoran army officers tried to cover up the army's responsibility for the murders. The testimony would also indicate that a number of officers -- not just one, as the army has insisted -- may have been involved in planning to kill the Jesuits.

Buckland's statement also supports the view that the decision to kill the priests, whose deaths came at the height of a major offensive by leftist guerrillas, was rational and premeditated, not hastily taken in the heat of battle, as defenders of the army have maintained.

Top-ranking Salvadoran army officers have told reporters that Buckland's original story is false and that he must have been "emotionally disturbed" to have concocted such a tale.

Buckland's statement, which at times is detailed, focuses on Col. Guillermo Benavides, the head of the Salvadoran military school and the officer who eventually was arrested and charged with seven other soldiers in the deaths.

In a handwritten affidavit, Buckland said the Salvadoran army chief of staff, Col. Rene Emilio Ponce, dispatched an officer to dissuade Benavides from taking action against the priests about Nov. 6 -- 10 days before the killings.

Buckland said that he accompanied the officer, Col. Carlos Aviles, to and from the meeting, but did not attend the session between Aviles, who was in charge of army psychological operations, and Benavides. At the time, Buckland was the American adviser to the army unit run by Aviles.

Buckland said Aviles met with Benavides and another, unknown Salvadoran officer. He recounted the following conversation with Aviles after the meeting:

"Aviles . . . told me that . . . Col. Benavidez {sic} is from the old school, he liked to handle things in his own way in the old style. Benavidez stated to Aviles that he wanted to do something about the priests . . . {and} they wanted to handle it the old way by killing some of the priests."

In addition to using the word "they" to describe those threatening the priests, there are other indications that Benavides may not have been the only officer involved. Buckland suggests that there may have been widespread talk of killing the Jesuits, whose advocacy of social justice and a negotiated end to the Salvadoran civil war had long been viewed with hostility by Salvadoran soldiers and rightists.

"I felt unconcerned {the killings} would happen," he wrote, "because other people were talking along those lines and I didn't feel the El Salvadoran armed forces would do something about it.

"Also because chief of staff Ponce assigned a senior colonel {Aviles} to address the problem I felt that if there was any validity to this talk it would not happen. I didn't think they would do something that foolish."

Despite a number of details that give Buckland's original statement an air of plausibility, Buckland recanted it in another interview with the FBI a week later. He said he had been "completely helpless and confused" when he gave the first statement.

"Upon reflection of those statements, I know that they are not true," he said. "I had no specific prior knowledge about the murders of the Jesuit priests or any specific plans or threats against them."

Aviles, who told the Associated Press that Buckland "is crazy," said he was on vacation with his family in New Orleans in the first two weeks of November -- the period in which Buckland says he accompanied Aviles to the miltary school.

U.S. Rep. Joe Moakley (D-Mass.), head of a special task force on El Salvador, accused the U.S. Embassy of withholding the Buckland testimony from Salvadoran judicial authorities. The testimony was delivered to the court handling the Jesuit case last week, nine months after Buckland gave it to the FBI. "If the information is correct," Moakley said, "Salvadoran military authorities should have considered Col. Benavides the prime suspect immediately after the murders took place."

Instead, it took nearly two months until further testimony by Buckland -- that Aviles had told him on Dec. 20 that Benavides ordered the killings -- broke the case and led to the arrests of Benavides and the others in January.

Judge Ricardo Zamora of the 4th Penal Court said the investigation is nearly complete. But legal wrangling and appeals could consume months before Zamora decides whether a trial will be held.