Kremlin, 7 Republics OK a Confederation : Soviet Union: The new group, if formed, would have a much weaker central government. Five republics skip the meeting.

Soviet President Mikhail S. Gorbachev and the leaders of seven Soviet republics reached agreement in principle Thursday on a new, much looser political confederation--”the Union of Sovereign States”--to succeed the monolithic Soviet Union.

But their meeting at an estate outside Moscow was not attended by leaders of five other, key republics. And much remains to be done before the new governmental entity is born.

Nevertheless, the mood among the leaders was markedly upbeat. “It is hard to say how many states will enter the union, but after today’s discussion, I have the firm conviction that there will be a union,” Russian Federation President Boris N. Yeltsin said.

Details of the blueprint agreed to, in theory, by Gorbachev and the republic leaders remained murky, and the document may have been kept vague to avoid scuttling the talks.

Russian television’s “Vesti” news program said that the most controversial aspects of a formal political agreement were apparently omitted and must be resolved in subsequent--and probably bitterly disputed--documents.

After eight hours of what Yeltsin said were “stormy” talks, the leaders agreed in principle to unite their lands in a new “Union of Sovereign States”-- Soyuz Suverennykh Gosudarstv-- supplanting the Union of Soviet Socialist Republics, in existence since 1922.

Ten republics have already agreed to join a Common Market-style “economic community,” and Kazakhstan President Nursultan Nazarbayev cited that fact as the chief reason for seeking a formal mechanism for political cooperation, too. “We see that the economic agreement that we have signed is difficult to implement because of the absence of a political union,” he said.

A draft of the Union Treaty, prepared for signing in August, was a direct impetus for the unsuccessful attempt by Communist conservatives to oust Gorbachev that same month. But the failed coup only hastened the meltdown of the super-centralized Soviet Union, establishing Yeltsin and leaders of the other republics as political players of the first rank.

Speaking to reporters after the session of the State Council, the collective executive that groups the Soviet president and leaders of the individual republics, Gorbachev said that participants agreed on founding a “confederative democratic state” where there would be “an immense redistribution of powers” downward.

“The republics delegate to the union (only) the functions that can be exercised more effectively at the union level,” he explained. “And they are resolutely against reviving the old center. I share this stand, but on one condition--that this be a great state with effective authorities. . . .”

But Gorbachev admitted that he had to give ground in the closed-door talks, apparently to the detriment of the central government’s powers and prerogatives.

Yeltsin said the State Council members examined as many as half a dozen compromises before opting for the union plan, which would maintain some vestiges of “centralized state authority.”

Gorbachev’s hopes for a political union were blessed by leaders of Russia, Kazakhstan, Azerbaijan, Belarus, Kyrgyzstan, Tadzhikistan and Turkmenistan.

He played down the absence of officials from the Ukraine and Uzbekistan. Uzbekistan President Islam Karimov is ailing, Gorbachev said. Ukrainian leader Leonid Kravchuk told him that his Parliament has put off discussing the Union Treaty until after Dec. 1, when Ukrainians will elect a president and vote on independence.

The presidents of Moldova and Georgia, which are bent on political independence, also stayed away, as did Armenia’s president, who is visiting the United States.