A Russian judge sentenced jailed former oil tycoon Mikhail Khodorkovsky to six additional years in prison on Thursday after convicting him on multi-billion dollar theft and money-laundering charges.

Moscow judge Viktor Danilkin granted the prosecutors' sentencing request and said Khodorkovsky would serve a total of 14 years in prison, including time served since his arrest in October 2003, meaning he is to remain in jail until 2017.   

Western officials had said the guilty verdict raised doubts about the Kremlin's commitment to the rule of law and human rights, and they were closely watching the case.

The outcome of Khodorkovsky's second trial could cause friction with Europe and strain the "reset" that has improved ties between the United States and Russia.   

Russia said the trial was a matter for its courts and rejected as "groundless" US suggestions that the verdict resulted from selective justice. - Reuters