"The Moscow City Court turned down an appeal in the case," said Anna Usachyova, the head of the court press service.
The decision to freeze the company's shares came into effect in September as part of a criminal probe into the company's former owner, Mikhail Gutseriyev, who is currently being sought by Russian authorities on a variety of charges, including fraud and tax evasion. Gutseriyev denied the charges.
If tried and convicted, Gutseriyev faces up to six years in prison, in a case reminiscent of legal battles for the now bankrupt oil firm Yukos.
The Yukos case was widely seen in the West as targeted against its founder Mikhail Khodorkovsky for funding the opposition and as part of a Kremlin campaign to regain control of oil and gas assets.
When the allegations were first announced, Gutseriyev said he had no plans to sell the company or move his assets overseas, but later said he would pass control of the holding to a new owner capable of resolving RussNeft's problems.
The announcement coincided with reports that BasEl, owned by Kremlin-friendly tycoon Oleg Deripaska, intended to buy Gutseriyev's former company.
BasEl is awaiting a decision from the anti-monopoly authorities on the deal.
RussNeft is Russia's seventh-largest oil company, producing around 3% of the nation's total crude output.