President Reagan yesterday described anti-government guerrillas in Nicaragua as "freedom fighters," and said action by Congress to cut off U.S. financial support for them would set "a very dangerous precedent" because "it literally was taking away the ability of the executive branch to carry out its constitutional responsibilities."

Reagan made his remarks during a rambling and sometimes confusing 35-minute Oval Office interview with reporters from six news organizations. A transcript of the interview was made available to other White House correspondents. He took issue with Tuesday's vote by the Democratic majority of the House Permanent Select Committee on Intelligence to cut off covert U.S. aid to the guerrillas fighting the left-wing Sandinista government in Nicaragua.

Acknowledging that the United States was directly aiding and "providing subsistence" to the anti-Sandinista forces, Reagan expressed support for their objectives and said he hoped that what he called an "irresponsible" House committee vote would be overturned in the Senate.

During the interview, Reagan sometimes interrupted himself and strayed from the subject as he sought to explain administration policy on Central America, arms control and the Middle East. Without indicating he knew he was doing so, Reagan also contradicted the position of the State Department in discussing the policy on nuclear arms adopted Tuesday by the U.S. Roman Catholic bishops.

Some of the reporters who participated in the interview said afterwards that the president at times appeared to have difficulty concentrating on the questions and his answers to them.

Questioning the legitimacy of the Sandinista government in Nicaragua, Reagan said: "And what really--other than being in control of the capitol, you might say, and having a handle on all the levers--what makes them any more a legitimate government than the people of Nicaragua who are asking for a chance to vote for the kind of government they want."

Reagan said it was right to refer to the anti-Sandinista forces as "freedom fighters" while the leftist, anti-government rebels in neighboring El Salvador should be described as "guerrillas." But he became confused at one point and called the leftist forces "the freedom fighters in El Salvador."

The administration's major argument for giving covert financial aid to the anti-Sandinista guerrillas has been that the U.S. assistance is confined to trying to halt shipments of arms and supplies to the leftists in El Salvador and is in no way directed at the overthrow of the Nicaraguan government.

But Reagan made almost no reference to this yesterday and talked instead about grievances of the anti-government guerrillas in Nicaragua, who he contended had been "betrayed" by the Sandinista regime.

He also opposed a provision of the House bill that would replace the covert aid to the anti-Sandinista guerrillas with above-board financial aid to friendly governments in Central America for surveillance and interdiction of arms supplies in their own countries.

The president discussed this provision as if the proposal permitted continued but open financial support of the anti-Sandinista guerrillas through these countries, which the bill does not do.

Asked if he would funnel the aid to the U.S.-supported guerrillas through other countries, Reagan responded: "No, I was saying that's what the committee said, that the committee said we would have to go over it, and, then, in going over it, you can only give money to another government. And if you did that, then you would have to be depending on--well, maybe those other governments in Central America would give that money to the freedom fighters in Nicaragua.

"Now, if they want to tell us that we can give money and do the same things we've been doing--money, giving, providing subsistence and so forth to these people directly and making it overt instead of covert--that's all right with me. I just don't want the restrictions put on it that they might put on."

This was the most direct statement yet by an American official of the role that the United States is playing in aiding the anti-Sandinista forces.

When Reagan was asked in a follow-up question whether he would be willing to accept the idea of overt aid to the anti-Sandinista guerrillas, he replied: "Yes, but not if they do it as one individual or more than one has suggested on the Hill--that they would do it and, then, we would have to enforce restrictions on the freedom fighters as to what tactics they could use.

"And I have said that if we were to do that, then I would expect that the only fair thing would be that the Nicaraguan government would itself impose the same restrictions on the freedom fighters in El Salvador, only I don't call them freedom fighters because they've got freedom and they're fighting for something else. They're fighting for a restraint on freedom."

Reagan also was asked whether he agreed with the warning of CIA Director William J. Casey that a "blood bath" would occur if the CIA were forced to stop supporting the guerrillas in Nicaragua.

"Well, I haven't heard his entire remark in connection with that term, or how he described it, or what he meant by it," Reagan said. "I'll make a point to find out. I once used a 'blood bath' term as governor of California, and one individual reversed it to the press and had it saying the opposite of what I had intended it to say, and I never did quite get the situation cleared up."

Reagan was referring to a comment he made at a meeting of the California Council of Growers at Yosemite, Calif., on April 7, 1970. Urging alumni of the California institutions of higher learning, which had experienced disruptions and demonstrations, to "stand up" in defense of university and college administrations, Reagan had said: "Now's the time to say, 'If it takes a blood bath now, let's get it over with.' Appeasement is not the answer."

The remark caused a stir in California after it was quoted accurately in a wire service story. An aide said afterward that a tape had to be played back to Reagan before he would believe that he had used the "blood bath" phrase.

During yesterday's interview, Reagan was asked how he would respond to critics who say that his foreign policy "is unsuccessful and that it's produced nothing."

"Well, I say that that's a very distorted picture," Reagan responded. "And I think that we've made great progress. Beirut is no longer being shelled on a daily basis around the clock, 15 hours of bombardment in one day. Yes, we are down to negotiating--sure, there are incidents--but we are down to negotiating the withdrawal of foreign forces after eight years of combat and invasion and harassment from outside as well as inside in Lebanon.

"With regard to western Europe, I do not believe that the NATO alliance has ever been any more solid than it is now . . . . The same thing is true in Asia and Japan . . . . I could wish that we could move faster in some of these things. And when you say the arms talks, as I said before, it took seven years for the SALT talks."

The reporter followed this question by citing specific accomplishments of the Carter administration in foreign policy at a similar point in the previous president's term and asking Reagan to name anything, "besides the opening up of Beirut," that he had achieved.

Reagan responded that relations with the People's Republic of China had been normalized by Richard M. Nixon, whom he identified only as "a previous president," and that he wasn't sure Carter "had added anything to what had already been accomplished."

In answering questions about adoption of a pastoral letter Tuesday by the U.S. Roman Catholic bishops calling for a halt in the nuclear arms race, Reagan said, "I think that too much attention was being paid to the one word 'curb' or 'halt' when you think there's 45,000 words in toto."

On April 6, a statement issued by the State Department hailed as a victory the substitution of the word "curb," which was underlined in the statement, for the word "freeze," used in an earlier draft.

Reagan yesterday brushed aside the decision of the bishops to oppose continued production, testing and deployment of nuclear weapons, saying that he hadn't received the statement and that "45,000 words are a lot to digest."

But he also said, "I have had some information in advance about it which indicates that it really is a legitimate effort to do exactly what we're doing, and that is to try to find ways toward world peace. And if so, then we're both doing the same thing."

However, hours before the interview with the president yesterday, Alan Romberg, deputy spokesman at the State Department, denounced the bishops' statement, saying that "a call for a halt on production and deployment, as a priority, would have the practical effect of diminishing the prospects for achieving the deep reductions that we are seeking at the nuclear arms control talks in Geneva."

Reagan also was asked during the interview whether he had a plan to proceed without the Palestine Liberation Organization if the PLO declined to participate in the process of Middle East peace negotiations. The president said this would require the agreement of the Arab states, and "we have to recognize their positions with regard to this."

Reagan also made a point of saying, as he has in the past, that the leadership council of the PLO "certainly was never elected by the Palestinian people--there are millions of Palestinians--and are they going to stand still for their interests being neglected on the basis of an action taken by this group, the PLO, which, as I say, was never elected by the Palestinian people?"

Asked whether he would like to see a referendum among the Palestinians to determine whether they should have other leadership, Reagan replied:

"If such a thing were practical and could be worked out--I don't know, in the scattered nature of them, there are Palestinians in virtually every country in the Middle East. I don't know whether you could ever get them together and bring about what--or even do the educating of them. I don't mean that word to sound demeaning or degrading to them but I mean the informing so that they could go in with some concept of what they were voting on."

The president was interviewed by George Condon of Copley News Service, Bruce Drake of the New York Daily News, Sara Fritz of U.S. News and World Report, Carl Leubsdorf of the Dallas Morning News, Chris Wallace of NBC and Steven Weisman of The New York Times. Two networks, ABC and CBS, declined overtures to participate because cameras were not allowed for this interview.

The interview was the second experience with a new format in which a group of reporters is selected by the White House to interview the president, with the content made immediately available for use by other news organizations.

While the six interviewed Reagan in the Oval Office, other reporters listened over a public address system in the White House briefing room, occasionally breaking into laughter or making puzzled comments about the president's answers.

Assistant press secretary Anson Franklin said that senior staff members were "surprised" when he told them of the reporters' responses. "We thought he did well," Franklin said.

Some of the unofficial reaction by White House aides was less sanguine.

"The president was tired," one official said.

Another added: "Let's face it, everyone has bad days and good days. Maybe this wasn't one of his good ones."