With relief tempered by caution, the Reagan administration yesterday welcomed the Israeli-Palestinian cease-fire arranged, after unusually delicate negotiations, by special U.S. envoy Philip C. Habib.

President Reagan cabled Habib a "well done," along with "my deep appreciation and admiration," shortly after receiving word that the Israeli cabinet had agreed to the terms brought by the U.S. diplomat from the Arab side.

Indeference to Israeli sensitivity about any agreement or relationship with the Palestine Liberation Organization, the White House and the State Department steered clear of the term "cease-fire," saying instead that the warring parties have agreed to "a cessation of hostilities."

Secretary of State Alexander M. Haig Jr. called the arrangement "a very encouraging first step," and White House spokesman Larry Speakes said it was "a hopeful and encouraging sign ont he road to achieving peace."

However, administration officials would not assess chances that the cease-fire would be long lasting, nor would they discuss the political calculations or considerations that brought the two sides to accept it.

"They've called it [the fighting] off, and I think that's the really big news, the thing that's been accomplished here," Reagan told reporters during a tour of the National Museum of American Art.

Informed administrationofficials discouraged the idea that broader agreements had been reached inthe process of negotiating the cease-fire. "This is all we've got a present," said one official. "We have to take one thing at a time."

In public references and private comments, administration officials gave a major share of the credit to Saudi Arabia. It apparently acted as a conduit to the PLO, which the United States does not formally recognize or negotiate with, as well as a source of pressure, directly and through Syria, on the Palestinian movement.

Official spokesmen in Washington said there has been no change in U.S. policy toward the PLO. But Haig, asked in an early morning CBS-TV interview about PLO conpliance, replied inunusually complementary terms that the cease-fire "has taken a degree of moderation and responsibility on all sides."

State Department spokesman Dean Fischer spoke of "Israel and the PLO" as the parties to the cease-fire. He said Habib's indirect negotiations with the Palestinian movement were "just a recognition of reality" rather than U.S. diplomatic recognition of the PLO.

Habib's success in stopping the fighting came as a surprise to most of Washington, although senior officials knew for at least a day that a deal was in the works. That knowledge, sources said, was among the reasons for the administration's sudden halt to Washington criticism of Israeli Prime Minister Menachem Begin.

Asked if the earlier criticism had been pressure on the Israelis, Haig said: "I think it serves no useful purpose to engage in that kind of Washington fun and games."

The welcome news cuts short, at least for the time being, a potentially damaging dispute between the United States and Israel arising from sharply increased Israeli military action across the Lebanese border with U.S.-built warplanes and other weapons.

It also relieves fro the moment an unusually strong U.S. reaction against Israeli use of force, especially the bombing raids a week ago that killed hundreds of Lebanese civilians in Beirut.

In an effort to stem the public reaction, a senior Israeli Embassy military official yesterday separately briefed Washington officials of Jewish community lobbying groups and about 20 diplomatic correspendents of U.S. news organizations on the recent military activity.

The officer, who asked not to be identified, called the bombing raid on Beirut "an exceptional activity related to the severity of shelling" in recent weeks by Palestinian military units.

Israeli policy has not changed to the extent of deliverately going after civilians, the officer said. At the same time, he said there could be a repetition of civilian-area bombing raids if it there is a repetition of the heavy shelling.

In New York, leaders of 34 American Jewish organizations urged Reagan in a joint letter to go ahead with delivery of F16 fighter planes to Israel. The administration has suspended the delivery because of the Israeli raid on an Iraqi nuclear facility and the bombing of Beirut.

Haig would not say when the warplanes would be released, but declared "we are going to be watching the situation very carefully in the hours, days and perhaps weeks ahead." Officials hinted that a continuation of the cease-fire would likely lead to release of the F16s.

The Saudi role in arranging the cease-fire may affec the timing and outcome of the administration's effort to supply sophisticated air surveillance aircraft, known as AWACS, to that country. This proposal has been delayed for several months due to opposition from Israel and members of Congress.