HELSINKI, OCT. 20 -- Secretary of State George P. Shultz said today he made no major progress toward restarting the Middle East peace process in five days of intensive discussions, reducing the already slim chances for diplomatic momentum between Arabs and Israelis in the remaining 15 months of the Reagan administration.

"I think we're a little ahead but I really can't point to much on the peace process . . . Realistically I can't point to any particular thing that moves matters forward," said Shultz, summing up his meetings since last Friday with Israeli, Saudi and Egyptian leaders in their capitals and King Hussein of Jordan last night and today in London.

"We will keep working at it," Shultz said. But his inability to produce a breakthrough, new impetus toward a breakthrough or even the "creative ideas" he had hoped to find left little optimism that lower-level or less intensive U.S. efforts could move the parties toward a drive for a broader peace.

Restarting and extending the Middle East peace process, especially to deal with the future status of the Israeli-occupied West Bank and Gaza Strip, was the first and one of the most ambitious efforts of Shultz' tenure as secretary of state. But after its surprise announcement on Sept. 1, 1982, the Shultz-initiated "Reagan plan" for Mideast peace bogged down in the Lebanon conflict and seemed almost to evaporate after the early 1984 U.S. pullout from Beirut, which Shultz opposed.

The Mideast swing he has just completed, en route to U.S.-Soviet meetings in Moscow Thursday and Friday, was Shultz' first trip to the Middle East in 29 months. Given the urgent priority of U.S.-Soviet relations, the Persian Gulf and Central America, the trip was considered by many to be Shultz' final Mideast peace initiative.

Summing up his impressions on his way to Helsinki after a luncheon meeting in London with Hussein, Shultz said an international peace conference as demanded by the Jordanian monarch is still fraught with difficulty. He also suggested that greater emphasis should be given to the substantive issues that would have to be settled between Arabs and Israelis if and when negotiations get underway.

The substantive problems, which include territorial issues as well as questions of autonomy, control and independence in the West Bank and Gaza, present "a very rocky road, too," Shultz said.

Shultz had threelengthy and separate meetings in Israel with both Prime Minister Yitzhak Shamir and Foreign Minister Shimon Peres, who hold different positions on Mideast peace issues. There were reports that Shultz was seeking to obtain enough of a shift from Shamir, with the concurrence of Peres, to induce Hussein to shift some of his positions.

A U.S. official traveling with Shultz said some gaps were narrowed, but far from enough to suggest a start of new Arab-Israeli negotiations.

An important factor is the revived Mideast diplomacy of the Soviet Union, which sent its deputy foreign minister, Yuli Vorontsov, on what U.S. aides said were hastily arranged visits to Egypt, Jordan and Syria just days before Shultz' trip.

Shultz said Shamir still had "a problem" in according the Soviets a role in an international conference. In particular, Shultz said, "it depresses him {Shamir}" that the Soviets voted last week to exclude Israel from the United Nations General Assembly even while saying they are interested in improving relations with Israel.

"The Soviets are pushing very hard for an international conference" but the kind of conference they describe is "exactly the kind of conference the Israelis are shy of and I agree with the Israelis," said Shultz. He said the effort must be intensified to find out exactly what kind of conference is intended and how it would work.

Some reports in Israel suggested that Shultz was interested in arranging a U.S.-Soviet sponsorship of Arab-Israeli negotiations under less formal auspices than a full-fledged international conference and also would not include other non-Mideast powers. Shultz gave no indication today that this was a promising idea.

Shultz is expected to discuss the Mideast peace process, among several other regional questions, with Soviet leaders when he arrives in Moscow Thursday.