The panel reduced Khodorkovskii's prison sentence to eight years from nine.
"The punishment will come into force," Reuters quoted Judge Vyacheslav Tarasov as saying. "The hearing is over. I ask the guards to take the convicted man away."
He was expected to begin serving his sentence immediately.
Khodorkovskii and his co-defendant, former Menatep head Platon Lebedev, were both sentenced in May
after a yearlong trial that many observers believe was politically motivated. Lebedev's conviction was also upheld today, and his sentence reduced to eight years in prison
State Prosecutor Dmitri Shokhin said today that Khodorkovskii's conviction was legally justified and accused the former oligarch and his supporters of falsely creating "the image of a martyr."
However, one of Khodorkovsii's defense lawyers, Yurii Shmidt, said after the decision that "the court did not take into account any of our arguments. We are going to fight this further. How we go about that I do not yet know. We have some time to think," Reuters reported.
The decision essentially ended Khodorkovskii's legal battle, although he still has the option of appealing to the Russian Supreme Court.
Khodorkovskii, who was once Russia's richest man, recently announced from his jail cell his intention to register as a candidate
in a parliamentary by-election in December. However, the election commission in the Moscow constituency in which he planned to run said earlier this week that it had not received his application, and today's confirmation of his conviction makes him ineligible to run for office.
(ITAR-TASS/Ekho Moskvy/RIA-Novosti/Reuters)See also:
Legal Dispute Stalls Khodorkovskii Appeal
A Verdict As Long As 'War And Peace'