President Reagan has decided to release to Israel the 75 F16 jet fighters that he had ordered held until that country agreed to withdraw its forces from Lebanon, administration officials said yesterday.

The announcement, which may come today, is a U.S. gesture of cooperation with the Jewish state following the signing earlier this week of the Lebanese-Israeli peace agreement.

The actual withdrawal of Israeli forces depends on a parallel withdrawal by Syria and the Palestine Liberation Organization, which have attacked the agreement and show no sign of cooperation.

Secretary of State George P. Shultz, who negotiated the final stage of the Lebanese-Israeli accord in 17 days of shuttle diplomacy, told a House subcommittee that U.S. diplomatic efforts are under way to build support for the pact in the Arab world and thus indirectly persuade the balking parties.

Shultz said that "the view of other Arab countries is developing very strongly that Syria should withdraw."

As part of the U.S. effort, Reagan's special Mideast envoy, Philip C. Habib, flew to Saudi Arabia last night for immediate discussions with King Fahd, according to reports from the Middle East. Saudi Arabia is considered among the most influential Arab nations and, in Shultz' view, supports the U.S. effort to obtain withdrawal of all foreign forces from Lebanon.

On Wednesday, the Syrian government refused to accept a visit from Habib to continue the dialogue begun by Shultz with President Hafez Assad in Damascus nearly two weeks ago.

Shultz, testifying before the House Appropriations subcommittee on foreign operations, sought to minimize the significance of Syria's snub. He quoted Damascus officials as saying "they didn't think they had anything to talk to him Habib about right now."

He added, "They made it clear, however, that doesn't mean they don't want to continue the dialogue with the United States."

For his part, Shultz demonstrated willingness bordering on eagerness to deal with Syria. Speaking of Syria's "legitimate concerns" about the Lebanese situation, Shultz said "there's lots to discuss."

Asked if he would return to Damascus if the Syrians will not accept Habib as a U.S. interlocutor, Shultz said he has no plans to return to the area soon, but added that "if it would be helpful, I will." In answer to the same question, Reagan, in an interview with United Press International, said: "If it's called for, of course, he'd go in a minute."

The sale to Israel of the F16s, the most advanced warplanes in the U.S. arsenal, was scheduled for presidential approval last June, but was held up after Israel invaded Lebanon. For months, the administration refused to admit that the delay was connected to the Lebanon situation, but on March 31 Reagan disclosed publicly that the sale would not proceed until Israel agreed to withdraw its troops from Lebanon.

Delivery of the planes is scheduled to begin in 1985.

Shultz' appearance before the House subcommittee centered on two world hot spots, the Middle East and Central America, and at one point the secretary tied them together, in a way that brought reactions from the lawmakers, by comparing El Salvador with Israel.

Rep. Clarence D. Long (D-Md.), the subcommittee chairman, asked Shultz to apply in Central America the same enthusiasm for negotiations he had shown recently in the Middle East. Shultz replied that "negotiations can work" in Central America as well but then, in a reference to the administration's requests for military aid for El Salvador, added that nobody would think that the Mideast talks would have succeeded if Israel were "unarmed, weak and unsupported."

Long, who has taken an unusual personal interest in Central America, said the difference between Israel and El Salvador is that "Israel, when you give them weapons, will fight."

Rep. Sidney R. Yates (D-Ill.), a strong supporter of Israel, said it is "an unworthy comparison" to discuss Israel and El Salvador in tandem.

Long pressed Shultz for some indication that the newly named U.S. special negotiator for Central America, former Florida senator Richard Stone, will be given sufficient flexibility to make concessions to leftist forces as part of a negotiated end to the fighting.

Shultz, however, gave no sign of sympathy with this viewpoint. He stressed that government negotiators must follow instructions approved by the president, and cautioned against being forced into "salami-slice tactics" involving the granting of major concessions. Shultz said the government should "stand pretty firm" on that.

The Middle East negotiating process, according to Shultz, centers at the moment on discussions between Lebanon and Syria, and between Lebanon and the PLO. That is "where the action is," Shultz told the lawmakers.

Syria, he said, has been "flexing its Soviet muscle." He decried the infusion of Soviet military equipment and personnel there, but expressed confidence that, in the end, "proud and independent" Syria will make its own decision about its future.