Credit Suisse Group AG is under fire from U.S. regulators over concerns the bank isn't heeding warnings to stop making loans regulators see as risky, the Wall Street Journal reported today. The Swiss bank in recent weeks received a letter from the Federal Reserve demanding that the bank immediately address problems with its underwriting and sale of leveraged loans, or high-interest-rate loans used by private-equity firms and others to finance purchases of companies, among other uses. The letter to Credit Suisse found problems with the bank's adherence to guidance issued last year, warning banks to avoid deals that included too much debt or too few protections for the lenders in case of a default.