Rosneft's chief financier Dmitry Avdeyev has stepped down from his position following the oil producer's completed acquisition of TNK-BP in a $55 billion deal, according to local press.

Vedomosti daily said that Avdeyev, who previously worked for Morgan Stanley as investment banker, left Rosneft, Russia's biggest oil producer, through mutual consent.

Kommersant business daily also hinted through its unidentified sources that Rosneft has appointed Svyatoslav Slavinsky, a Citigroup senior banking services executive, as its new vice president for finances.

Rosneft recently announced that it had completely acquired TNK-BP from the AAR consortium of Soviet tycoons and BP.

The deal is the biggest in the Russia's corporate history.

A spokesman of Rosneft declined to comment on the matter.