Federal bank examiners have not acted quickly or strongly enough in enforcing laws intended to prevent terrorists and other criminals from laundering money through U.S. banks, according to an internal review released yesterday by a key bank regulatory agency.

The study, which reviewed the way regulators have monitored banks with a history of inadequate controls, found that problems have been allowed to fester.

Eight of the 36 banks in the sample had failed to correct problems cited by the Office of the Comptroller of the Currency (OCC), the report said.

The OCC's initial actions "have not always been severe enough to ensure timely correction," and "follow-up actions have not always been timely or effective," the report by the OCC's Quality Management Division said.

"There are banks supervised by the OCC with significant . . . deficiencies that have not been fully addressed," the report said.

The review was prompted by problems at Riggs Bank, which pleaded guilty in January to a felony charge of failing to file federally mandated suspicious-activity reports on the finances of former Chilean dictator Augusto Pinochet and officials of Equatorial Guinea.

The Treasury Department's inspector general has been investigating why the OCC allowed violations at Riggs to persist for years.

"The OCC has got to get tougher to prevent terrorists and other criminals from using our financial system against us," said Sen. Carl M. Levin (D-Mich.), who led a Senate investigation of Riggs.

OCC spokesman Robert M. Garsson said that "the supervisory action just hadn't been adequate to the task," but he said the agency has been making improvements. "We feel we have a program in place that will get the job done," Garsson said.

The review focused on the controls banks employ to prevent or detect money laundering and did not determine whether money laundering was actually taking place. In addition, it focused on what happened after regulators had documented procedural violations and did not determine how thorough examiners were in detecting violations.

For large- and mid-size banks, supervision "has shown improvement, but remains marginally adequate," the report said.

In examining large banks, regulators do not routinely follow the prescribed procedures, which some examiners consider "too extensive to complete," the report said.

The report said 22 percent of the banks in the study failed to correct deficiencies, compared with 40 percent of the banks in a review of the period from 2000 to 2003. But 8 percentage points of the seeming improvement reflected banks leaving OCC supervision by failing or changing their charters, and 5 percentage points of the seeming improvement involved banks' unverified claims that they had made corrections.

Krista Shonk, regulatory counsel for America's Community Bankers, an industry group, said there have been "a number of unanswered questions with respect to what is expected of institutions." But, Shonk added, "I don't think that there's a community banker out there now that is brushing off . . . compliance."