A Time magazine correspondent acknowledged today that he had no source for a key detail in a controversial article about former Israeli defense minister Ariel Sharon and had "inferred" it from leads, hunches and strong hints by other Israeli officials to whom he spoke confidentially.

The testimony by David Halevy, the magazine's Jerusalem correspondent, came in response to persistent questioning by the judge in Sharon's $50 million libel suit against Time Inc. and under examination by Sharon's lawyer, Milton S. Gould.

At issue was a Time article saying that the secret appendix to Israel's Kahan Commission report on the massacre of hundreds of Palestinians in Beirut had included minutes of a meeting Sharon had held with Lebanese Christian Phalangist leaders the day before the killings began.

Halevy said he felt confident about the story.

"It was my evaluation," the journalist testified, "my analysis based on my knowledge of 43 years living in Israel."

Halevy said he and Time's Jerusalem bureau chief Harry Kelly "obviously reached a conclusion that there is a case against Minister Sharon between the lines" after reading the public sections of the Kahan report when it was published in February 1983.

The commission found that Sharon bore "indirect" responsibility for the killings because he disregarded the possibility they would occur when he allowed Phalangist militiamen to enter the refugee camps. The three-member commission recommended that Sharon be stripped of his post as defense minister.

Halevy said that recommendation struck him as being out of proportion to the findings on Sharon they put into the public record, leading him to believe that evidence that Sharon had a deeper involvement in the massacres was "hidden" in the secret appendix.

"It is very clear that the commission is hiding between the lines a lot of information related to meetings between Minister Sharon and the commanders of the Phalangist leadership, the political leadership of the Phalangists . . . . ," Halevy said.

Gould, who had called Halevy as a "hostile witness," suggested that the reporter had been guessing or speculating when he and Kelly composed the dispatch for Time writers and editors in New York.

Judge Abraham D. Sofaer directed the lawyer to refrain from such remarks.

But it was the judge, closely questioning Halevy, who elicited the correspondent's acknowledgment that no one had told him that the secret appendix contained minutes of Sharon's meetings with the Phalangist leaders.

A single paragraph from the Feb. 21, 1983, Time article on the Kahane Commission's report is at issue.

It says Time had learned that the secret appendix to the report contained details of a conversation Sharon had with the family of slain Phalangist militia leader Bashir Gemayel at the Gemayel estate in the Lebanese town of Bifkaya the day before the massacres began. The Time paragraph alleged that Sharon "discussed" the need for the Phalangists to "take revenge" for Bashir's assassination.

Halevy has testified that the first tips he got about the conversation came months before the commission report was released. In a December 1982 memo he sent Time editors for internal circulation, Halevy reported that his sources had told him that Sharon, in the conversations with the Gemayels, "gave them the feeling . . . that he understood their need to take revenge of the assassination of Bashir nd assured them that the Israeli Army would neither hinder them nor try to stop them."

Halevy testified here that the information for that memo was developed from four Israeli government sources, including two generals and an "intelligence person." He said that he learned from them that notes from the Bifkaya conversation were taken by an intelligence officer and later turned over to the Kahane Commission.

In February, when the commission report was released, Halevy said he went back to two of his sources on a hunch that the minutes of the Bifkaya meeting were in the secret appendix.

The correspondent said that when he asked one of the generals about that, the only response he was able to get was, "It all started at Bifkaya. Go back to Bifkaya and check Bifkaya."

Halevy said he then called a high-ranking government official, another of the four sources for the December memo.

The official refused to discuss the content of the classified appendix but did agree to characterize what was in it, saying it was basically a reference book and index including the names of intelligence agents who were referred to only by codes in the sections of the report that were made public.

Halevy said he asked the government official if the names of operatives who had taken notes at Bifkaya and other meetings Sharon had with Phalangist leaders were included.

The official responded affirmatively, Halevy said. After hanging up the phone, the correspondent went into the office of bureau chief Kelly and gave him the thumbs-up signal and they filed their report, saying the conversation was in the appendix.

But today when Sofaer asked Halevy if the government source had said "parts of testimony" were in the appendix, Halevy responded, "No. He said it's a reference book. It's an index, it's a code."