By Alexei Anishchuk
MOSCOW (Reuters) - A jailed former Russian oil tycoon kept up his fight against the Kremlin on Monday, filing for parole following last week's court decision to keep him in jail for 13 years.
Once Russia's richest man, Mikhail Khodorkovsky was arrested in 2003 after falling out with then-President Vladimir Putin in a case his supporters say is politically motivated.
Khodorkovsky and his business partner Platon Lebedev were sentenced to stay in jail until 2017 in a second trial last December, but last week a Moscow court reduced that by one year to a total of 13 years.
The two will now remain in prison well into 2016. Khodorkovsky has repeatedly denied any wrongdoing. Last week's ruling gave Khodorkovsky, who has served half of the sentence, the right to be pardoned without pleading guilty.
"I ask the court to consider the issue of my parole," he wrote on his official website www.khodorkovsky.ru.
"I do not acknowledge my guilt, because I am challenging the court's (previous) decision in the European Court of Human Rights and Russia's Supreme court."
Their previous attempts for parole have been dismissed by the authorities. The European Court of Human Rights is to consider the case on Tuesday.
Lebedev has also filed a parole plea, the website said.
President Dmitry Medvedev, who succeeded Putin as president, adopted a softer tone in remarks made earlier this month, spurring hopes for Khodorkovsky's early release.
Now prime minister but is still seen as Russia's most powerful politician, Putin has maintained a tougher stance, saying in December the tycoon was a thief who should be in jail.
Government critics describe the prosecution of Khodorkovsky as part of a Kremlin campaign to tighten state control over oil revenues and punish the tycoon for perceived challenges to Putin, president from 2000-2008.
In the second trial, Khodorkovsky is charged with stealing billions of dollars of oil from his Yukos company's subsidiaries through price mechanisms and laundering some of the money.
The case has become as symbol of injustice, highlighting that Medvedev's pledges to ensure the rule of law have fallen short. Western governments have condemned the December verdict, saying it raised questions about Russia's commitment to justice.
(Editing by Maria Golovnina)