President Reagan strongly indicated here today that he favors a review of the insanity defense in criminal trials to establish either a new guilty-but-insane verdict or to shift the burden to the defense to prove that the accused was insane.

Although Reagan made a point of saying he was disassociating his comments from the controversial decision in the case of his assailant, John W. Hinckley Jr., he broke a silence on the issue self-imposed since a District of Columbia jury acquitted Hinckley on grounds of insanity on June 21.

Reagan noted that the Justice Department was reviewing proposals for a guilty-but-insane verdict.

He added that he believed that much of the criticism of the Hinckley jury's decision stemmed from the "fact that the ruling placed on the backs of the prosecution the need to prove that someone was sane rather than the other way of proving that he was insane.

"And, you know, if you start thinking about even a lot of your friends," Reagan added, "you have to say, 'Gee, if I had to prove they were sane, I would have a hard job.' "

Reagan's comments came at a luncheon here with about 75 western editors and broadcasters as he began an 11-day vacation at his ranch in the mountains north of Santa Barbara.

In response to questions from the editors, Reagan said that he did not believe Secretary of State Alexander M. Haig Jr. had resigned because he wanted to run for president, as some Arab leaders have suggested.

He said he did not think the resignation would affect the progress of arms reduction negotiations with the Soviet Union that began on Tuesday.

If he thought it would have, Reagan said, "I would not have accepted but fought against accepting the resignation."

At his press conference Wednesday night, Reagan denied telling aides that he would not run for reelection in 1984. He said it would be "unlike" him to "walk away from an unfinished job."

Today White House political director Edward Rollins, who accompanied him, said that "right now he could beat any Democrat" and that the hint that Reagan will run again will be "helpful" to Republican candidates this fall.

Reagan repeated a denial he made at his press conference, saying Israeli Prime Minister Menachem Begin had never given him assurances in their June 21 meeting in the White House that Israeli forces would not enter Beirut.

Three days after that meeting, deputy White House press secretary Larry Speakes told reporters that Begin had made such a pledge. Speakes said today he had talked to Reagan before briefing reporters.

But Reagan said Begin expressed to him the intention that he "did not want to invade . . . "

Reagan said that when he first heard about Speakes' report he thought that Begin perhaps had made those assurances in meetings with other U.S. officials.

It was only later, he said, that he realized that the account was based on reports of his one-on-one meeting with the Israeli prime minister.

The confusion was a "case of the second hand repeating--maybe even third hand--within the shop of the conversation I had had with Begin which was a conversation just between the two of us," Reagan said.

Asked why he had not acted more quickly to correct Speakes' account, Reagan said, "As soon as I realized that it was based on my conversation with Begin I corrected the fact."

That was Wednesday night, six days after his spokesman Speakes gave the version Reagan now disavows.