MOSCOW, JUNE 12 -- After months of confrontation with Moscow, the presidents of the three separatist Baltic republics said that they had made significant progress today in their first joint meeting with Soviet leader Mikhail Gorbachev since the secession crisis began earlier this year.

The private meeting followed a key public concession from Gorbachev, who gave up his demand that the republics rescind their declarations of independence before he would contemplate formal negotiations on Baltic independence.

Baltic sources said after the meeting that a compromise formula for such talks is likely to include an end to the Soviet economic embargo against Lithuania and that Gorbachev told the three leaders their republics might be given special legal status during a "transition period."

Although the Kremlin and all three Baltic legislatures will have to agree on terms for independence talks, the Baltic presidents said they were delighted by Gorbachev's "new attitude." "For the first time, we felt not like the elder and the younger, but rather like legal equals," said Latvian President Anatolijs Gorbunovs. Lithuanian President Vytautus Landsbergis said: "For the first time, we didn't just speak past each other."

Just hours before the Kremlin meeting, the legislature of the Russian republic met in another wing of the vast complex and voted overwhelmingly to declare sovereignty. The declaration carries little legal weight, but it is clearly a framework for a new constitution for the Russian republic and a powerful challenge to centralized Soviet authority over the country's 15 constituent republics.

Led by Boris Yeltsin, Gorbachev's political rival and the new president of the Russian republic, the legislature passed the measure 907 to 13. Although the declaration of sovereignty does not amount to an assertion of independence as did those passed in the Baltics, it does demand that Moscow diminish control over the republic's economy and political life.

The legislators voted, however, not to change the name of the republic from the Soviet Socialist Republic of Russia, which covers two-thirds of the Soviet Union from the Baltic to the Pacific and is more populous than all other Soviet republics combined.

Yeltsin's election to the Russian presidency and his immediate attempt to establish direct economic and political contacts with the Baltic leaders helped lead Gorbachev to seek a compromise on the secession issue, Baltic sources said. "Pressure from the West during the Washington summit may have helped, but the decisive factor clearly was the victory of democratic forces in the Russian republic," said Estonian legislator Igor Gryazin. "For the first time Gorbachev has showed a real willingness, a true desire, to solve the Baltic problem.

"After all, real Baltic independence can exist only if we have a democratic Russia in the neighborhood. An unstable and economically weak Russia would be a threat to our three small republics."

{Secretary of State James A. Baker III, in testimony to the Senate Foreign Relations Committee, said he did not believe U.S. and Soviet positions were any closer on the subject of Lithuania as a result of the recent U.S.-Soviet summit. Baker said "we believe we heard a commitment to compromise" from Gorbachev and that he is encouraged that Baltic leaders are in Moscow for talks, "but a practical narrowing of the Soviet and Lithuanian difference is yet to be seen."}

For weeks, Gorbachev has insisted that the Baltic republics must repeal their declarations of independence before he would agree to any structured negotiations on secession. Now he has changed that position, saying in a speech to the Soviet legislature before meeting with the three presidents that "if Lithuania will suspend the implementation of this act of independence, we may start to talk. That means suspend its implementation at least for the duration of the talks." A shift from demanding repeal of the declaration to suspension of the laws passed afterward to implement it, represents a significant difference in the eyes of Lithuanian legislators, who say they were elected this year for the purpose of passing the declaration.

The Baltic presidents, for their part, seemed equally prepared to make concessions to Moscow to get negotiations started. The most radical of the three, Lithuania's Landsbergis, appeared to take a softer view of Gorbachev after today's meeting and seemed more optimistic about finding a compromise.

But Landsbergis said that "under no circumstances can we hold negotiations" while the Soviet economic embargo continues. Moscow's reduced shipments of oil, gas and other goods to Lithuania have left tens of thousands of people out of work and forced the republic to live on a severe austerity plan.

Landsbergis, asked if he were hopeful about a compromise and an end to the embargo, smiled and said, "Maybe things will not be better tomorrow, but as for the day after tomorrow, let's just wait and see." Although he refused to suggest the terms for any such compromise, Landsbergis said that Gorbachev wanted both sides "to act all at once."

"Look, I understand that Gorbachev has a lot of pressure on him, too," Landsbergis said.

The three Baltic republics were annexed by the Soviet Union in 1940 as the result of a pre-World War II pact between Joseph Stalin and Adolf Hitler. Between 1920 and 1940, Estonia, Latvia and Lithuania were independent and members of the League of Nations.

Landsbergis, Gorbunovs and President Arnold Ruutel of Estonia also participated in a meeting today of one of Gorbachev's two top-level advisory groups, the Federation Council, which includes the presidents of all 15 Soviet republics. Yeltsin also attended the session, at which Gorbachev reportedly talked of the Soviet Union's becoming a looser federation of sovereign states.

Landsbergis said that since Lithuania's declaration of independence he felt it was inappropriate for him to take part in the work of Soviet governing bodies except as a guest or observer. He said he participated today, however, because it gave him the opportunity to meet with Gorbachev. He added that he was "interested" in Gorbachev's plans for a renewed Soviet federation "but only from the point of view of an independent Lithuania."

The Federation Council members discussed "the urgent need to work out and conclude a new union treaty that will guarantee the actual economic and political sovereignty of the union republics and their effective interaction," the Soviet news agency Tass reported.

Meanwhile, in the Soviet Central Asian republic of Kirghizia, another 32 deaths have been reported in ethnic clashes between Kirghiz and Uzbeks. That brings to 139 the number of people killed in the regional violence since June 2, Tass said.