The Finance Ministry extended the repayment period for OAO Sberbank, VTB Group and OAO Gazprombank to three months from one week. The benchmark Micex stock index plunged as much as 10 percent, taking its three-day decline to 25 percent.
Russia's financial markets are facing the biggest test since the 1998 crisis that pushed the government to default on $40 billion of debt and devalue the ruble. Global turmoil sparked by the collapse of the U.S. subprime mortgage market has led to a drying up of lending between banks and this week forced Lehman Brothers Holdings Inc. into bankruptcy.
The cost of lending has soared to a record, with the MosPrime overnight rate reaching 11.1 percent today, deterring speculative bets in equities. Russian stocks have lost more than $425 billion in value since reaching an all-time high May 17.
Oil production, the government's biggest source of revenue, and accelerating inflation are adding to concerns for investors. Crude output is falling for the first time since 1998 and the inflation rate advanced more than expected in August, to near a five year high of 15 percent.
The ruble-denominated Micex Stock Exchange suspended trading indefinitely at 12:10 p.m. after its index erased a 7.6 percent gain and plunged as much as 10 percent within an hour. The benchmark fell 17 percent yesterday, the biggest decline of the 88 indexes tracked by Bloomberg. The dollar-denominated RTS halted trading after similar declines.