MOSCOW, September 29. /ITAR-TASS/. Shares of Russian holding company Sistema owned by billionaire Vladimir Yevtushenkov plunged by 10% on the Moscow Stock Exchange on Monday to 15.3 rubles ($0.39) per share.

Yevtushenkov, ranked by Forbes among Russia’s 20 richest people with an estimated fortune of $9 billion, was placed under house arrest in mid-September on suspicion of involvement in a case of illegal privatization of oil companies in the Urals Republic of Bashkortostan.

Experts say a further plunge in Sistema shares was caused by a decision passed by a Moscow court on Thursday to extend the house arrest for Yevtushenkov until November 16.