Sual could sell its 15.8 percent stake in RusAl, Vedomosti reported on Monday, citing two sources.
One of the sources said preliminary talks on the matter are underway, but a possible sale is a long way off. A Sual representative denied the story, while RusAl declined to comment.
According to a shareholders agreement, Oleg Deripaska's En+ has the right of first refusal for the stake, which the newspaper said is worth $3.97 billion. Deripaska formed RusAl in 2007 by combining his own company with Sual and Glencore's alumina assets.