Foreign banks will find it tough to enter the booming Russian market and could find it yet harder to win market share outside the top slice of corporate business, Russian and foreign bankers said Tuesday

With markets in Western Europe saturated and most of Central Europe's banking assets acquired by overseas players, Russia's booming economy is seen as an attractive new option. Citigroup of the United States; Austria's Raiffeisen; International Moscow Bank, a German-Nordic venture; and France's SociОtО GОnОrale have all targeted Russian retail banking. Many foreign banks have also gone after investment banking business as Russian companies have set about raising billions of dollars on international markets. Germany's Deutsche Bank says it wants a stake in Russian investment bank United Financial Group. Even Russian banks, which have grown fat on booming stock and debt markets, are facing a big change as they are forced to turn a ruble from the domestic economy, bankers said. Trading debt and equity is hugely profitable, and according to Cynthia Stone, head of the Russian office of credit rating agency Standard & Poor's, accounted for 40 percent of banking revenues and 50 percent of net income in the first nine months of this year.