As the case files indicate, in October 2016, Ulyukayev demanded a $2 million bribe from Sechin for the Economic Development Ministry's consent to the go-ahead for Rosneft's acquisition of a 50.08% stake in another oil company, Bashneft.
Ulyukayev is seen as a member of the liberal camp in the Russian ruling elite, while Sechin - a longtime former deputy chief of staff at the Kremlin - is perceived as a hard-liner and one of Putin's closest allies.
Ulyukayev, who became economic development minister in 2013, was arrested at Rosneft's headquarters past year after being handed a bag containing $2m by Sechin, who had asked security forces to set up a sting.
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Since the agreement was made, the Russians have flown into coalition airspace six to eight times per day. During the encounter, coalition leaders contacted the Russians to try to ease the situation.
Ulyukayev denied the charges, calling them a provocation set up by Sechin.
Sechin has not attended the court hearings despite being summoned as a witness. Asked Thursday about Sechin's failure to show up, Putin said at his marathon news conference that he saw no violation of legal procedures by his lieutenant.
Ulyukayev was taken into custody in the courtroom. The judge also ruled that he should be held in a maximum security prison. Ulyukayev said the sentence was "unjust" and vowed to appeal.
In his final arguments earlier this month, Ulyukayev accused Sechin of staging a "horrific and cruel provocation" against him.
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Ulyukayev claims he was tricked by Sechin and believed that a bag full of cash that he accepted from Sechin contained a gift of rare wine - not $2 million in cash. Russian media say that Sechin, an avid hunter, has a habit of presenting his high-level connections with baskets of sausages from his own butcher's shop.
Although Sechin provided written evidence to the court, an unusual move, he refused to appear in court for cross-examination.
Ulyukayev pledged to devote the rest of his life to "defending people's interests".
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