Russian oil tycoon Mikhail Khodorkovsky walked out of a Russian penal colony Friday and boarded a private jet to Germany, ending a decade of incarceration for the country's most famous prisoner after at least two years of stealthy negotiations.

The tycoon's release and subsequent airlift—eight months ahead of his sentence's end—unfolded with the same secrecy and drama of his 2003 arrest, when government agents took control of his private plane on a Siberian tarmac and hauled him off at gunpoint. At the prison in the Russian...