Yeltsin Yields to Critics, Will Quit 1 Job : Russia: President to leave prime minister’s post. His treaty to keep federation unified gets an ovation.

Russian President Boris N. Yeltsin rode to his own political rescue once again on Friday, appeasing his enemies in Parliament with a promise that he would soon resign as prime minister and proudly accepting credit for keeping Russia from splitting apart.

After sitting, stone-faced, for more than two days as conservative lawmakers of the Russian Congress of People’s Deputies savaged his government and policies, Yeltsin swung suddenly into action Friday and delivered a one-two punch.

Making concessions to his conservative critics, he promised to resign from his post as prime minister, while remaining president, in about three months and to hire some new ministers and fire some old ones and change the government’s structure by the end of the year.

And he won a standing ovation for his Federation Treaty, an agreement intended to keep Russia from falling apart as the Soviet Union did, after the Congress ratified it by an overwhelming 848-10 vote.

“Russia was, is and will remain whole, unified and strong,” Yeltsin declared majestically to the nearly 1,000 deputies in the Grand Kremlin Palace.

The 61-year-old president did not appear to have needed much persuasion to resign as prime minister. He took on the job late last year to put his full authority behind the painful economic reforms his Cabinet has undertaken, but he acknowledged that he had a hard time coping with his double position.

“I realize that the combination of posts of president and prime minister is very hard, above all on me,” Yeltsin said. “In another three months, once it is clear that there will be no return to the past, that the reforms are irreversible . . . I’ll undoubtedly introduce proposals on a candidate for prime minister. Don’t force me to do it at once.”

Yeltsin promised to formulate a new organic law for the Russian government that would, in effect, deprive him of his interim powers to rule by decree, but he asked that it not take effect until December. Deputies had proposed a deadline of one month, but Yeltsin argued that a month was far too little time.

The Russian president pledged to streamline his personal bureaucracy, shake up his Cabinet and appoint an additional deputy prime minister to be in charge of industry--”a candidate who will impress you.”

A final vote was not scheduled until this morning, but deputies appeared amenable to Yeltsin’s request for more time and were expected to agree to it.

“A decisive turnaround in the course of the Congress has taken place after Yeltsin’s speech,” said lawmaker Victor Sheinis, a strong Yeltsin ally. “Now, it is important to secure it.

“Today is the decisive day, and it is necessary to rally all democratic forces,” he added at a news conference.

Along with the president’s own charisma, Yeltsin’s backers had a powerful political lever left to them--the threat that if conservatives made too many cuts in the president’s power, they would “appeal to the people” by staging a referendum on the president’s role and perhaps calling early parliamentary elections.

Leaders of Democratic Russia, a movement that unites Yeltsin’s most active supporters, said they were prepared to gather the signatures needed to call a referendum. They have also threatened mass demonstrations.

Sergei M. Shakhrai, Yeltsin’s top legal adviser, hinted that Yeltsin’s supporters were also considering calling for a referendum on their draft of the new Russian constitution, which would retain a strong presidency in contradiction to lawmakers’ demands for a stronger Parliament.