Lenders would be required to depend on stable funding from sources such as deposits, according to a proposal written by the Federal Deposit Insurance Corp., Office of the Comptroller of the Currency and Federal Reserve. Most megabanks already comply with the plan, which aims to guarantee each has sufficient funding to survive for as long as a year.

After years of new regulations governing banks’ capital, leverage and liquidity, the net stable funding ratio is among the last of the major constraints spurred by the 2008 financial crisis. The proposal -- the U.S. answer to a 2014 agreement among international regulators -- would add to an earlier demand that lenders maintain a 30-day stockpile of easy-to-sell assets for shorter periods of stress. Both aim to ensure banks don’t have to scramble for funding in a meltdown.

The proposal would insist that banks maintain funding “including capital, long-term debt and other stable sources over a one-year window to account for the liquidity risks arising from their assets, derivatives and off-balance-sheet activities,” FDIC Chairman Martin Gruenberg said in a statement before the vote and released Tuesday. 

The regulators would push lenders to rely less on repurchase agreements that expire quickly and were an industry mainstay in the years before the financial crisis. Their plan focuses on 15 banks with more than $250 billion in assets or more than $10 billion in foreign exposures on their balance sheets. A related proposal from the Fed will impose less-stringent requirements on 20 firms above $50 billion.

Almost all of the covered banks currently meet the proposed requirements set to take effect in 2018, according to regulators’ estimates, and the few that don’t are almost at the mark. The firms would have to report their holdings on a quarterly basis, the regulators said.

Goldman Sachs Group Inc. and Morgan StanleyMorgan Stanley -- New York-based investment banks that didn’t have as much of a customer-deposit base as the commercial banks -- have amassed deposits at a rapid clip since the 2008 crisis. Goldman Sachs stands to gain even more ground with its new online bank acquired from General Electric Co. last week.

In 2007, a surge in subprime-mortgage defaults led creditors to shorten the duration on funding they offered. As the situation worsened, banks became increasingly reliant on short-term financing that became harder to obtain. To head off similar scenarios, the new proposal calls on lenders to maintain more longer-term funding such as customer deposits. Harder-to-sell assets will need to be backed by higher levels of funding.

Fed Vote

The Fed is set to vote May 3 on the U.S. plan, which is tougher than the Basel version, most notably in terms of what assets count as the most liquid. The central bank has already targeted stiffer rules at the firms most reliant on short-term funding in the form of a capital surcharge established last year.

The Fed also stood alone earlier this month in declaring municipal bonds liquid enough to be in the basket of assets a bank can use to build its short-term stockpile. But this longer-term proposal gives munis a more universal treatment, saying they need funding equal to half of their value. That means munis fall right in the middle of the liquidity range. 

The net stable funding ratio proposal will be opened for public comment through Aug. 5. Only after reviewing the comments will the three agencies be able to implement a final rule.

This latest demand comes as financial firms face rising pressure from regulators, including new constraints on bonuses and rejection of “living-will” plans from five banks. As President Barack Obama’s administration winds down, federal agencies have been trying to finish rules, some of which have been delayed for years.

The new liquidity plan “enters an already-crowded field of recent rules targeting liquidity risk in banking,” Jeremy Newell, general counsel of the Clearing House Association, said in a statement. The industry group will be looking at whether it’s “truly coherent with, and complementary to, these other existing requirements.”