A tentative agreement to approve a new government under Boris Yeltsin to tackle Russia's economic crisis appeared to collapse within hours Sunday after the Communists said they would not accept the deal.

The Communist turnabout came just after the government and the opposition said they had reached a deal following days of tough behind-the-scenes bargaining to call a political truce to win quick confirmation of Yeltsin's choice for prime minister.Communist leader Gennady Zyuganov said the proposed pact was rejected by a meeting of his party leadership because there was no firm guarantee Yeltsin would abide by its provisions. He did not rule out further talks.

"So far, the document is not guaranteeing anybody anything," he said, adding that the party would vote Monday against the confirmation of acting Prime Minister Viktor Chernomyrdin in parliamentary hearings.

The proposed three-page agreement would have given the State Duma, parliament's lower house, more say in Cabinet appointments but would have left Yeltsin with substantial power, despite earlier opposition calls for his removal.

In particular, the president would have retained control of the security forces with the right to fill three key posts - the defense, foreign and interior ministries. In exchange, Yeltsin would have agreed to Duma approval of most Cabinet appointments for the first time, according to lawmakers and media reports.

The Communists' surprise rejection of the deal could be a prelude to more bargaining as the opposition seeks further concessions. Russia may face weeks of political uncertainty if the opposition blocks Chernomyrdin's confirmation and Yeltsin refuses to withdraw it.

Chernomyrdin said earlier that swift formation of a new government was vital to tackle the nation's economic crisis.

"We must resolve financial problems. The ruble is hanging by a thread," he said.

In Washington, White House national security spokesman P.J. Crowley declined to comment on Yeltsin's troubles reaching a deal with the opposition, on the eve of President Clinton's visit.

"This is a matter for the government of Russia and the people of Russia," Crowley said. "We look forward to working with the new government. We hope they'll be put into place as quickly as possible."

Clinton arrives in Moscow on Tuesday for a summit with Russia's troubled leaders.

Russia was plunged into political and economic crisis when financial markets and the currency collapsed as the government defaulted on its debts and the country was hit by the global furor in developing markets. Ordinary Russians fear they face yet more hardships after years of upheaval, but there have been few signs of panic on the streets of Moscow and other cities.

The ruble appeared to gain Sunday and exchange points across Moscow were buying U.S. dollars at an average 8 rubles to the dollar, down from an average of 81/2 rubles to the dollar the day before. The rate had been 6 rubles to the dollar before the collapse.

There had been no immediate confirmation that Yeltsin would accept the deal, even though it left him with a firm grip on power. But he appeared reluctant to accept many of the provisions, according to Russian media.

There was no word on an economic plan that had been discussed with the opposition to handle the crisis. It called for imposing some Soviet-style economic controls, but Chernomyrdin said Saturday there was no question of restoring the Soviet system.

While Yeltsin would have lost some power under the deal, it had appeared to represent a major step down by the hard-line opposition, which had been calling for the president's removal and formal power sharing. Yeltsin said last week he would never resign.

Zyuganov called for unspecified changes to the International Monetary Fund's terms for extending a $22.6 billion loan to Russia. The Communists also called for formation of a Constitutional Assembly, a new body that would take over "if the situation gets out of control" and tighter controls on Yeltsin's powers to nominate a prime minister.

Yeltsin brought Chernomyrdin back as prime minister a week ago because he hoped the familiar figure would restore confidence in the government, badly damaged by the ruble's sharp decline.