Worldwide trading houses have stopped buying aluminum from Rusal because of the sanctions, according to executives at five companies that regularly buy from the company, who spoke on condition of anonymity due to the sensitivity of the discussions.
The sanctions - created to make it nearly impossible for Mr Deripaska's empire to do business in greenback - pose a grave threat to an oligarch who has been seen as one of Russian President Vladimir Putin's closest allies.
The action targeted Russian oligarchs whose companies have wide-ranging involvement in worldwide capital markets.
The Russian stock market also fell heavily.
"The biggest blow was taken by public companies controlled by Oleg Deripaska", Moscow brokerage Aton wrote in a briefing note, adding that the market was looking for "possible actions to minimise" the damage.
Rusal and seven other companies linked to Deripaska were the main targets when the U.S. imposed sanctions created to punish Vladimir Putin's inner circle for "malign activity", including support for Bashar al-Assad's government in Syria and interfering with the USA election in 2016. By making it virtually impossible for Deripaska's businesses to trade in U.S. dollars, the measures threaten the empire of one of Putin's closest allies. The latest sanctions affected companies such as Sberbank, whose shares fell 17% in Moscow.
The sanctions also hit Norilsk Nickel, whose shares were down 16 percent.
En+, Oleg Deripaska's energy business which listed in London in November, plunged 42 per cent, compounding losses suffered on Friday. Shares in Russian steelmaker Evraz were the biggest fallers on the FTSE 100 in London, closing 14.4% lower. Glencore is one of Rusal's biggest investors and buyers of its aluminium, and its chief executive, Ivan Glasenberg, sits on the Rusal board. It was mentioned that the USA sanctions are highly likely to will have a negative impact on the business of the company and its development. "This is an outrageous business from the point of view of illegality, from the point of view of flouting all the norms, and of course careful analysis is needed here", said spokesman Dmitry Peskov. It said further evaluations were being carried out to assess the impact of the sanctions.