JERUSALEM -- A year after opening talks on improving relations, Israel and the Soviet Union have intensified their dialogue but seem trapped by conflicting priorities in the effort to bridge their diplomatic breach of the past two decades.

Despite a rise in the number of Jews leaving the Soviet Union in recent months, Israel has won no formal commitment ensuring a steady flow of Jewish emigrants nor a promise of renewed diplomatic relations, broken off by Moscow in 1967. Meanwhile, the Soviet Union has failed to obtain Israeli acquiescence in Moscow's playing a more prominent role in the Middle East peace process.

It may be a measure of the importance of the dialogue, however, that both sides are pursuing the contacts despite the slow progress, according to analysts here. Following informal talks in Rome last April between Foreign Minister Shimon Peres and Soviet officials, and the arrival in Israel July 13 of a Soviet consular delegation, officials from the two sides held their most extensive discussions so far in Bonn last month.

Hebrew University political scientist Michael Agurski, an emigre from Moscow and leading Soviet specialist here, contended in an interview that, while the two countries may make marginal progress, "it's difficult to expect major improvements in the Soviet-Israeli relationship."

The most obvious problem is the clash of priorities within the governing Israeli coalition of the Labor alignment, led by Foreign Minister Shimon Peres, and the Likud bloc of Prime Minister Yitzhak Shamir. Nimrod Novik, a top aide to Peres who held the talks in August with Soviet diplomat Vladimir Tarasov, said a potentially "quite significant advance" had been made in crafting principles and a format for an international conference on regional peace.

The left-leaning Labor alignment is seeking an international conference with Soviet participation as a way to press Moscow's ally, Syria, into formally recognizing Israel's right to exist and to open negotiations with Jordan over the future of the Israeli-occupied West Bank. Peres' camp appears willing to focus on the conference, with bilateral relations to be resumed in the course of cooperation on the peace process.

But another Israeli official, speaking for the Likud, dismissed Peres' and Novik's optimism on a conference. The official said he had detected no change in Shamir's opposition to an international conference following the talks with Tarasov, who is the deputy director of the Soviet Foreign Ministry's Middle East section. "It's funny that {Novik} should talk about an international conference when this is something the Cabinet is not agreed on," the official said.

The official made it clear that Shamir and Israeli conservatives are willing to talk to the Soviet Union, but primarily about the emigration issue. "For us, the fate of Russian Jewry is more important than an international conference," said an Israeli official, explaining Shamir's view. "There are 400,000 Jews who crave getting out. Can we just forget them?"

Statements by Peres and Novik after the latest talks suggest no progress in accelerating Soviet Jewish emigration, a deeply emotional issue here.

Hebrew University's Agurski said that issue enables even a small group of Soviet emigres to generate heavy pressure against renewing ties to the Soviet Union or permitting it a role in peace-keeping.

Soviet emigre organizations have demonstrated at offices rented by the Soviet consular delegation in Tel Aviv, calling for Israel to withhold improved relations until Moscow allows free Jewish emigration. But Agurski says those activists benefit more from financial support by American conservatives than from popularity in the Soviet emigre community here.

Agurski said 70 to 80 percent of Soviet emigres here favor renewed ties. "Most of us would like good relations; we all have friends and relatives we would like to visit" in the Soviet Union, he said.

Aside from the Israeli infighting, a critical question for Peres' effort is whether the Soviet leadership is fully behind Tarasov's stance, which underlined that Moscow would not seek a conference with the power to impose a resolution of the Middle East conflict.

Israelis fear that such a conference would leave them isolated and under pressure to make concessions in that larger forum. Novik suggested that "a major deadline for signaling this is the third week of September," when the U.N. General Assembly meeting will offer chances for Soviet Foreign Minister Eduard Shevardnadze, now in Washington, to meet with Secretary of State George P. Shultz and Peres.

Agurski sees an imperative for the Soviet Union to enlarge its role in the Middle East. "They have 50 million Moslems and will have 100 million in 15 or 20 years," he said. "Especially with the Islamic causes in Iran and Afghanistan, Moscow faces the threat of a Moslem explosion in the Soviet south. The Soviets are looking for ways to neutralize this."

But, Agurski said, "the Soviet Union's Arabists will complicate moves toward Israel by demanding that they balance every move with a gesture to the Arab countries." As does the United States, the Soviet Union fears a spread of fundamentalist Islam, and will want a Middle East settlement that works against it, he said.

Agurski emphasized that the Soviet-Israeli relationship was really triangular, involving the United States as well. But, he argued, none of those countries has "solid decision-making in foreign policy. . . . Decisions made by negotiators are not necessarily binding on what are divided policy-making structures."

Agurski contends that Soviet domestic policy, long secondary to foreign policy goals, is challenging that order, complicating efforts to focus bureaucratic attention on Middle East policy.

Even the relatively optimistic Novik said the limited recent progress "will be irrelevant if we don't bridge the remaining gaps in a politically relevant time." He declined to elaborate, although analysts suggest that any momentum in a peace process will risk being dissipated early next year by U.S. preoccupation with the 1988 elections.

Backers of Peres' policy fear that a hiatus in peace efforts could raise frustration among Israeli voters, causing a shift to the right in elections scheduled in the fall of 1988.