The threatened breakup of Russia's largest oil company signals a broader shift away from the country's anything-goes, freewheeling market of the 1990s toward a new form of state capitalism as President Vladimir Putin's government asserts a greater role in the economy. A dozen years after Russia began divesting itself of old Soviet state assets, Putin's government appears to be bringing the era of mass privatization to a close.

For the first time since the fall of the Soviet Union, the government this year will buy substantially more assets than it will sell, part of a Kremlin attempt to reclaim more control, particularly over the strategic energy industry.

Putin disavows renationalization of private property, but his government's tax battle with Yukos Oil Co. represents only the most sensational example of the state's growing power. Officials began moving Wednesday to seize Yukos assets after the company of tycoon Mikhail Khodorkovsky -- in jail on charges of fraud and tax evasion -- failed to meet a court deadline to pay the first half of a $7 billion bill for back taxes. If the state follows through, it could assume ownership of Yukos refineries and wells or sell them off to favored firms.

"It's clear that the state is strengthening its control over the economy," said Vladimir Ryzhkov, an independent member of parliament and market reform advocate. "Business today is facing a lot of trouble. They're under attack from all sides. These are black days for Russian capitalism."

Putin appears to be creating a hybrid between the command economy of the Communist period and the free-market economy ushered in by his predecessor, Boris Yeltsin, according to analysts. Rather than further liberalizing the market, Putin has moved lately to impose his own rules and collect a greater share of industry's profits through taxation.

"It was inevitable that the reconstruction of the Russian state would require restructuring the results of privatization," said Stanislav Belkovsky, a political analyst with ties to a hard-line Kremlin faction and a leading promoter of reining in the tycoons who came to be known as oligarchs. "The Khodorkovsky case was crucial from this point of view."

The reassertion of state influence reflects a popular backlash against the often-rigged privatizations of the 1990s that made small numbers of people extremely wealthy. Vladimir Mau, an economist who helped develop market reforms then, said retrenchment was the normal reaction to revolution. "It's nothing which could not be found in the economic history of Western Europe," he said.

Aside from the Yukos case, the government has suspended plans to privatize parts of Unified Energy Systems, the state-owned electricity monopoly; repeatedly put off auctioning a controlling stake in Svyazinvest, a major state-owned telecommunications firm; and failed to follow through on promises to lift foreign ownership restrictions on Gazprom, the state-controlled natural gas monopoly.

In the biggest blow to a foreign company, the government in January annulled a 1993 tender allowing Exxon Mobil Corp. and its partners to develop the Sakhalin-3 project in the Pacific. It plans to re-auction the license for $1 billion or more.

A brewing banking crisis has provided another opening for the government to increase its role. Several banks have collapsed or restricted payments in recent weeks, most recently Guta Bank, which closed branches Tuesday. Depositors flocked to various banks to withdraw money, fearing a repeat of the 1998 financial crisis that cost many their life savings.

The government's response includes a plan for state-owned Vneshtorgbank to buy Guta Bank. "This may appear to be a reasonable solution in the circumstances, but it would also signal the first step in what could become a wider re-nationalization of the banking sector," Aton Capital, a brokerage house, said in a report Thursday.

Other than Yukos, the state's most significant plans for taking control of private property center on Gazprom, one of the country's largest companies and steward of the world's largest natural gas reserves. After selling off shares over the years, the state holds 37 percent of the company. Now the government plans to buy back just over 13 percent, worth about $5.3 billion, to retake a majority share.

Some analysts say Putin's Kremlin is planning to make Gazprom the nation's dominant energy company, akin to state-owned oil firms in the Middle East. Gazprom officials have talked about creating an oil subsidiary; the obvious place to pick up petroleum assets would be from Yukos, as one Gazprom executive recently suggested.

At the same time, the state has slowed the pace of privatization. In 2002, it sold $2.9 billion in assets; it has sold just $100 million so far in 2004 and has plans this year for just one major privatization, sale of its 7.6 percent share in Lukoil, the second-largest oil producer, for about $1.6 billion.

But the Lukoil sale would not offset the Gazprom buyback, meaning the state would acquire more assets than it divests in 2004 -- and more assets than it has sold during Putin's entire presidency.

Many analysts say this would be bad for economic development. "State ownership is an old-school recipe for inefficiency, with political patronage winning out over incentives to maximize profits," the Troika Dialog investment firm said in a report this week.

Moreover, even in releasing ownership in Lukoil, the state is not really surrendering control. Lukoil is a prime example of the Kremlin's favored version of private companies -- aligned with the state even if not owned by it. The company helped shut down a television station critical of the Kremlin, voluntarily gave up legal tax breaks and regularly coughs up funds for Kremlin pet projects, such as reconstruction of Konstantinovsky Palace outside St. Petersburg, used by Putin for state events.

The Kremlin has concentrated on reasserting influence over the energy industry, the driving force in Russia's resource-based economy. While the state still owns about 21 percent of the value of Russia's equity market, it retains just 4 percent of the oil sector, according to Troika Dialog.

Many political leaders accept the need for a greater state role in the energy sector. "It's a reasonable position, not only because it's a strategic industry but because the energy sector gives us at least 55 percent of exports and close to 25 percent" of gross national product, said Mikhail Zadornov, a former finance minister and one of the few members of a pro-market political party left in parliament.

The state does not need to take over companies to get greater revenue from them. A government study showed that the state and the oil firms evenly split $50 billion in profits last year; since then, taxes on oil above $25 a barrel have risen from 70 percent to 90 percent, and Prime Minister Mikhail Fradkov on Thursday suggested that the government impose another oil tax increase.

"As the owners of natural resources, it should have the right to get profits like any other owner," said Sergei Glazyev, a prominent former Communist economist.

The Khodorkovsky dispute stems in part from his challenges to state supremacy in the energy industry. Some in the Kremlin, according to analysts, resented Khodorkovsky's attempts to infringe on the pipeline monopoly of state-owned Transneft by proposing a new oil line to China. In a meeting with Putin, Khodorkovsky also challenged state-owned Rosneft's purchase of a lucrative oil field, implying that an inordinate sum had been paid to line the pockets of insiders.

"I'm not a supporter of oligarchs," said Mikhail Delyagin, a former government economics adviser who now works for the Motherland party. "But Khodorkovsky's problems appeared not because he's bad but because he was better than the others and he got really concerned with the problems the others were willing to put up with -- corruption, inefficiency of the state and others."

To some entrepreneurs and analysts, the real force behind the drive for greater control is the siloviki, or former KGB officers known as "men of power," who missed out on the 1990s sell-offs and now want in on the action.

It's "simple greed," said Yulia Latynina, a broadcast and newspaper commentator who specializes in money and politics. "I don't think the president or the people around him want to nationalize property. I think they want to redistribute property."

Even Belkovsky, the Kremlin-allied political analyst, is among people expressing disappointment with the Kremlin's handling of the Khodorkovsky case. Rather than single out one oligarch, he said, the government should require winners of corrupt privatizations to collectively give back up as much as $25 billion in exchange for legitimizing their purchases permanently. "The Yukos affair does not show such an approach," he said, "and I believe it unfortunately just repeats the logic of the 1990s."

Putin said the Yukos case would not lead to a broader review of privatization, but state auditors are now conducting a wide reexamination of 1990s sell-offs and have concluded that $1.6 billion was lost in crooked or undervalued deals.

Latynina said the state would not stop with Yukos. "Appetite comes when you are eating -- first Yukos, then everyone else," she said.

Russian President Vladimir Putin, right, talks with German Chancellor Gerhard Schroeder during a meeting in Moscow.