The Finance Ministry has moved to stave off worries that the troubles at U.S. mortgage giants Fannie Mae and Freddie Mac pose a threat to the country's gold and foreign currency reserves or the more than $157 billion it has salted away from taxes on energy exports.

The ministry said none of the oil funds had been invested in the mortgage firms and that the United States had issued assurances for any portion of Russian gold and currency reserves invested, out of a total of as much as $100 billion invested in three major U.S. mortgage companies, according to some sources

Fears that the U.S. government might have to bail out the country's two largest mortgage finance companies sent their shares tumbling last week and spurred a broader slump on the U.S. stock market.

Shares in the companies ping-ponged around Friday, rebounding slightly by close after initial drops of around 50 percent. Last week Russia's domestic markets fell slightly On the Russian markets, MICEX slipped by 2.7 percent for the week, with the RTS also declining.

The minor correction to the shares in Fannie Mae and Freddie Mac came as U.S. officials launched a salvage operation. On Friday, U.S. Treasury Secretary Henry Paulson said the government had no plans to take over the firms, while Senator Chris Dodd said they might be allowed to borrow funds from the Federal Reserve.

Federal Reserve Chairman Ben Bernanke told Freddie Mac CEO Richard Syron that the Fed could open its discount window to the two firms, Reuters reported.

Both Bernanke and Paulson told a congressional hearing Thursday that both companies were "adequately capitalized."

The $100 billion reportedly invested in the U.S. mortgage market would account for about 20 percent of Russian gold and foreign currency reserves, so the Finance Ministry moved quickly to report the U.S. assurances.

"In contrast to the price of shares in Fannie Mae and Freddie Mac, the value of their debt obligations will remain stable," the Finance Ministry said in a statement posted on its web site Saturday. "That is because the U.S. government has publicly announced its readiness to offer these companies financial support."

A contingency plan is in place by which the U.S. government would create a conservatorship to take over one or both of the mortgage companies, rendering their stock worthless, but guaranteeing their bonds and other debt obligations, reports in the U.S. media said.

In February, Russian Central Bank deputy head Alexei Ulyukayev said that "a few percent" of the country's $476 billion gold reserves were invested in the U.S. firms.

But the Central Bank upped its foreign currency holdings in Freddie Mac, Fannie Mae and U.S. Federal Home Loan Banks to 2.48 trillion rubles ($101 billion) last year, Vedomosti reported Friday, citing the Central Bank's year-end results for 2007.

The allocation of the country's gold reserves for last year was approved by the National Banking Council, the reserves' governing body, on July 10, the Finance Ministry statement said.

Despite reports in February that the rules for managing the National Reserve Fund or the National Welfare Fund — created in February when the stabilization fund was split between them — would allow the purchase of bonds from Fannie Mae or Freddie Mac, the ministry's statement said its current investment policy meant that it had no exposure to securities in the companies.

Since last summer's subprime crisis in the United States, Russia has sought to represent itself as an "island of stability" in an unstable economic world, thanks to its huge gold and foreign currency holdings and the receipts collected in the oil-wealth funds.

In his keynote speech to the St. Petersburg Economic Forum last month, President Dmitry Medvedev laid the blame for the current international downturn squarely on the shoulders of the United States.