The source added Rusal, the world's second largest aluminum producer, was still not shipping to customers around the world awaiting guidance from USA authorities.
"Oleg Deripaska agreed in principle with the chairman's request that Mr. Deripaska reduce his shareholding in the company to below 50%", En+ said.
The US government this month imposed sanctions on Rusal's billionaire owner Oleg Deripaska and several companies in which he is a large shareholder, including Rusal, in response to what the United States called Russia's "malign activities".
Two sources told Reuters yesterday that Rusal planned sweeping board and management changes in a bid to escape sanctions.
In the current situation, the company "reserves the right to use all legal measures to protect its reputation", RUSAL stressed.
The changes were announced on April 27 by Deripaska's En+ holding company, which owns 48 percent of Rusal, the largest aluminium producer in Russian Federation and the second-largest worldwide.More news: Home Secretary suggests government 'still working on' its position on customs union
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The changes in the board of directors and management team are being discussed with other shareholders, another source familiar with the situation said.
En+ also said it asked the USA for an extension of the deadline for operations with En+'s debt, equity or other holdings from 7 May to 31 October or another appropriate date.
The LME suspended Rusal's aluminium from its list of approved brands from April 17 after some members raised concerns about settling LME contracts with sanctions-hit companies.
Without the extension, En+'s ability to maintain its listing in London will be materially impacted, it said.
EN+ has lodged a desperate appeal with the US Office of Foreign Assets Control (Ofac) to allow it more time to comply with its demands to end Mr Derispaka's control of the company or face being frozen out of worldwide markets altogether.
In the United States, commenting on the decision Deripaska, said that the reduction of the stake in En+ do not necessarily lead to the exclusion of this company from the sanctions list. "If this (option) does not work out, then there will be the second option, which (Russian industry and trade minister Denis) Manturov talked about", the source said.