A Moscow appeals court upheld the second conviction of oil magnate Mikhail Khodorkovsky, but it also reduced his 14-year prison sentence by one year.
Tuesday's decision means that the 47-year-old Khodorkovsky, once Russia's richest man, will remain in prison until 2016. He and business partner Platon Lebedev were convicted in December of stealing tens of billions of dollars' worth of oil from Khodorkovsky's Yukos oil company and laundering the proceeds, a ruling that drew strong international condemnation.
Khodorkovsky was seen as a political threat to Vladimir Putin, who was president in 2003 when Khodorkovsky was arrested and remains Russia's most powerful leader now that he is prime minister.
Soon after the ruling was issued, Amnesty International declared Khodorkovsky and Lebedev, whose sentence was also reduced, to be prisoners of conscience.
"For several years now these two men have been trapped in a judicial vortex that answers to political not legal considerations," Nicola Duckworth, Amnesty International's director for Europe and Central Asia, said in a statement. "Today's verdict makes it clear that Russia's lower courts are unable, or unwilling, to deliver justice in their cases."
During the one-day appeal hearing at Moscow City Court, Khodorkovsky poured scorn on the verdict, a lengthy summary of the trial that spelled out his guilt.
"From which dusty basement did they dig out the venomous Stalinist spider who wrote that gibberish?" Khodorkovsky asked, visibly agitated as he paced around the glass and steel defendant's cage.
"What long-term investments are we talking about with a justice system like that? No modernization is going to happen without cleaning out these basements."
In wrapping up the defense's case Tuesday, lawyer Yuri Shmidt pointed to numerous contradictions in the verdict, saying they showed that the judge who presided over the 18-month trial could not have written the ruling on his own.
Khodorkovsky's barb also was aimed at President Dmitry Medvedev, who succeeded Putin in 2008 on promises to strengthen the rule of law as part of an effort to modernize Russia's economy and attract needed foreign investment. His efforts so far have had little effect.
"The president is going to have to make a choice," Khodorkovsky said. "What does he, Russia, need more: a state ruled by law or the opportunity for de facto extrajudicial reprisals?"
Khodorkovsky's father said he was deeply disappointed. "I had laid my hopes on Medvedev," said Boris Khodorkovsky. "It turned out to be just promises and promises."
As recently as last week, the president said Khodorkovsky would pose "absolutely no danger" to society if he were released.
Khodorkovsky's mother, though, said she had not expected any leniency. "We still have the same government and Putin is still around, so why would anything change?" said Marina Khodorkovskaya. "Because a thief would never let out a person from whom he stole and whom he imprisoned. That's all I can say."
After Khodorkovsky's arrest, Yukos oil company was broken up and sold off at bargain-basement prices to pay off back tax claims. Its main assets ended up with state-controlled Rosneft.
When the three-judge panel announced its ruling, shouts of "shame" could be heard from about 50 Khodorkovsky supporters watching the proceedings on a video screen outside the courtroom.
The defense has said the charges against Khodorkovsky and Lebedev reflected a lack of understanding of the oil business, including the payment of transit fees and export duties. Numerous witnesses, including current and former government officials, testified that Khodorkovsky could not have stolen the oil from his company.
The charges also contradicted the first trial, in which Khodorkovsky was convicted of evading taxes on Yukos profits.
"The authors of the sentence made themselves and the whole country look stupid by saying that victims of theft actually profit from it themselves, that it is a crime to strive for higher profits, that the price for oil on the international market should equal domestic prices," Khodorkovsky said.
His eight-year sentence for his first conviction, which also had been reduced by one year on appeal, is set to end in October. The new 13-year sentence is to run concurrently.
Prosecutors said it was not yet clear where Khodorkovsky would serve out his prison term. Following his first conviction, he was sent to a prison colony in the far east of Russia on the Chinese border, a tiring journey for his elderly parents.
His lawyers said they planned to appeal to Russia's Supreme Court and were already preparing a claim to file with the European Court of Human Rights.
AP writers David Nowak and Lynn Berry contributed to this report.