MOSCOW – An imprisoned business tycoon whose legal troubles have come to symbolize the limits of political freedom in Vladimir Putin’s Russia was found guilty Monday of stealing oil from his own company and is likely to face another decade behind bars.

Inside the Moscow courtroom, Judge Viktor Danilkin began reading the lengthy verdict against Mikhail Khodorkovsky and his partner, Platon Lebedev, in a rapid, almost inaudible monotone, not even pausing to look up. On the snowy street outside, several hundred supporters held portraits of the 48-year-old Khodorkovsky and demanded that he be freed.

The verdict agreed with prosecutors that Khodorkovsky, formerly the head of the Yukos oil company, and Lebedev had embezzled the equivalent of $27 billion worth of oil from their company. It said they “created an illusion of a market mechanism to set oil purchase prices to hide the illegal documentation of the unfair deals and eventually to steal the oil.”

Many Russians have concluded that Khodorkovsky’s long legal troubles are largely the result of a political vendetta by Putin, and have also helped concentrate wealth in the hands of Kremlin insiders. Khodorkovsky has said repeatedly that he was persecuted for supporting the political opposition soon after Putin took over as president in 2000. Putin, who is now prime minister, still is considered the most powerful man in the country.

The businessman is nearing the end of an eight-year sentence for tax evasion and fraud, but it has been widely anticipated in Russia that authorities would find a way to keep him behind bars.

Referring to Khodorkovsky, Putin said in recent weeks that “a thief should sit in prison.”

Khodorkovsky became fabulously wealthy in the lax atmosphere that followed the breakup of the Soviet Union. Assets that once belonged to the state fell into the hands of a small class of businessmen who became known as Russia’s “oligarches.”

Khodorkovsky turned to politics and social action, encouraging parties that sought a Western-style democracy as well as the successors to the Soviet Communists in a bid to foster a more open political system. He opened orphanages and funded university programs.

Many of the oligarches have faced prosecution or been forced to leave the country as Putin reasserted central control. The defense insisted during the trial that Khodorkovsky’s business activity was legal at the time, and it was absurd to accuse ex-Yukos leadership of stealing oil from themselves.

His lawyer, Karina Moskalenko, described the trial as “a theater of the absurd.”