Fed Proposes New Capital Rules for Banks

Under the proposals, which will be open for public comment until March 31, banks with more than $50 billion in assets would be required, for now, to maintain a cushion equal to 5 percent of assets even during periods of unexpected stress. That standard is up from 4 percent previously and from much lower levels maintained by some large banks during the growth of the housing bubble.

That 5 percent is also the same level that was outlined by the Fed last month when it laid out plans for another round of bank stress tests. But the Fed also warned that banks will be required to match significantly stricter international requirements in the near future, including a larger amount of required capital based on a bank's overall asset size.

The international standards, known as the Basel III accords, are expected to set capital requirements for the largest multinational financial institutions at 7 percent of capital plus a surcharge of up to 2.5 percent depending on a bank's overall risk levels. Those standards are not expected to be phased in until 2016, at the earliest.