While international regulators struggle to rewrite global risk-based  capital rules, here at home the Federal Reserve Board is quietly forging   ahead with new ways to supervise the world's largest banks.   
In two recent letters to bankers and their examiners, the Fed outlined  how its oversight of roughly 32 U.S. and foreign banking companies is   evolving.   
  
The first letter, dated June 23, explains that a senior examiner,  working with a team of specialists, will be assigned to each of these large   banks. The supervisors will assess a bank's risk management processes and   monitor its risk profile. Oversight will be tailored to the institution's   principal business lines and risks, and its performance will be compared   with its peers', according to the 10-page letter.         
The second letter, dated July 1, zeros in on how these "large complex  banking organizations" determine how much capital to hold. 
  
These banks-roughly 20 U.S. banks and 12 foreign banks operating here-  must "tie the identification, monitoring, and evaluation of risk to the   determination of the institution's capital needs," according to the 11-page   letter.     
In other words, banks must integrate capital setting with risk  management. 
"This is a bombshell," said John Mingo, who left the Fed's supervisory  staff this month to start a consulting firm. "This is the most important   supervisory letter ever published, because for the first time it requires   the large banks to have internal capital measurement procedures."     
  
In fact, the Fed said it decided to write this letter after a survey of  a few large banks showed that current practice "could be significantly   improved."   
"Most banks have a long way to go in terms of establishing a consistent  internal economic capital measurement process across all business lines, or   all kinds of risks," Mr. Mingo said.   
Both letters build on the recent regulatory trend toward focusing on the  quality of a bank's internal controls and risk management. 
The Fed wants a bank be able to demonstrate, through an internal  analysis tailored to its particular business lines, that capital is   adequate to support the risks it is taking. A cushion for unexpected events   should be included.     
  
The Fed told examiners not to expect immediate compliance.
"Examiners should evaluate an institution's progress ... considering  progress both relative to the institution's former practice and relative to   its peers," the letter states.   
For now, the results will affect the "management" grade in a bank's  Camels rating. Eventually, the Fed said, the capital grade will also be   affected. (Camels is a 1-5 system rating a bank's capital, asset quality,   management, equity, liquidity, and sensitivity to risk.)     
The Fed acknowledged that there is no one right way to determine  internal capital needs. But it is clear that it is no longer enough to   merely satisfy regulatory capital requirements.   
"With the growing scope and complexity of business activities," the Fed  said, "supervisors ... cannot rely on risk-based capital ratios as   indicators of capital strength."   
Still, international regulators, including the Fed, will continue to try  and improve the risk-based capital standards. A June 3 proposal issued by   the Basel Committee on Bank Supervision would base capital requirements on   the riskiness of a bank's borrowers. Under current rules, capital is based   on the type of assets a bank holds. Comments on the proposal are not due   until March 31 and a final rule could take years to develop.         
"We're working with them on a new Basel accord, but at the same time  we're moving ahead more quickly than that process to assess the quality of   internal capital measurement," Mr. Mingo said.