A Russian court on Tuesday rejected an appeal by the embattled Yukos Oil Co. in its multibillion-dollar tax battle with the government, clearing the way for authorities to begin impounding bank accounts or seizing assets in a matter of days.

The ruling came after a hearing in which Yukos representatives proposed a financial settlement that they said would stave off bankruptcy. But government officials in the courtroom refused to consider the plan and ruled out any negotiations, despite recent comments by President Vladimir Putin and top aides that appeared to open the door to a deal.

Two weeks ago, Putin said he did not want to see the company go into bankruptcy. Industry analysts said at the time that Putin appeared to want a resolution that would punish Yukos and force out its major shareholders without breaking up the company, Russia's second-largest oil producer.

Yukos stock, which had recovered somewhat after Putin's statement, fell 5 percent Tuesday on news of the ruling.

The tax fight has run on a parallel track to a criminal case brought against Yukos's imprisoned chief shareholder, Mikhail Khodorkovsky, who faces trial this summer on fraud and tax evasion charges. The legal action against Khodorkovsky, his partners and his company has been widely seen as a power struggle between Russia's political leader and its richest citizen.

In Tuesday's ruling, the Moscow appeals court upheld a $3.4 billion claim against Yukos for taxes, penalties and interest from 2000, filed by the government after it reopened audits for that year and applied a more restrictive interpretation of tax shelter laws. Yukos officials said the company would appeal again but expressed fear that the government would now begin moving to collect.

"We think that today's decision is completely illegal," company attorney Sergei Pepelyayev said in a telephone interview. With the court's blessing in hand, he added, tax officials "can now demand all the money at once, but they should realize it's not possible" for the company to pay in a lump sum.

Pepelyayev said the court would take five days to put its decision into writing, and after that, marshals could be sent to seize Yukos funds, shares or other assets.

In the settlement offer rejected by the government on Tuesday, Pepelyayev said Yukos proposed paying about $1 billion in cash over two years in exchange for dropping the penalty, interest and some tax claims. Yukos has said it has about $1 billion in cash available.

"It's not that we agree that it's a legitimate charge, but we would rather have a bad peace than war," Pepelyayev said.

Investment analysts viewed the court ruling as the beginning of the final resolution in the Yukos case. Putin now has to decide what to do about Yukos, they said.

"The much anticipated 'doomsday' for Yukos dawned today with the decision," one Moscow brokerage, United Financial Group, told investors in a report issued Tuesday. It sketched out a variety of options, ranging from bankruptcy to the state stripping valuable production assets, but expressed confidence that Putin meant what he said and would preserve the essential form of the company. "This stage in the Yukos affair has seemed much less ominous since President Putin's declaration," the report said.

Viktor Gerashchenko, the new Yukos chairman, said the court ruling was "creating problems for the market, for domestic and foreign investors."