NEW YORK (AFP) - US regulators warned Tuesday that 11 giant banks have submitted unrealistic contingency plans in the event of bankruptcy, warning that unprepared lenders could plunge the world into a new financial crisis.

The Federal Reserve and Federal Deposit Insurance Corporation said the 11 titans, popularly known as "those too big to fail," must make better plans to restructure their firms in the event of failure.

FDIC Vice Chairman Thomas Hoenig said they had failed to show "how, in failure, any one of these firms could overcome obstacles to entering bankruptcy without precipitating a financial crisis." "The plans provide no credible or clear path through bankruptcy that doesn't require unrealistic assumptions and direct or indirect public support," Hoening warned.

The group comprises JPMorgan Chase, Goldman Sachs, Deutsche Bank, Bank of America, Bank of New York Mellon, Barclays, Citigroup, Credit Suisse, Morgan Stanley, State Street and UBS.

Under the Dodd-Frank Act enacted in response to the 2008 financial crisis, the banks must demonstrate a strategy "for rapid and orderly resolution" in the event of bankruptcy or major financial distress.

But the submissions by the financial giants fail to adequately prepare a so-called "living will" that could avert disaster, FDIC said.

The rule was intended to address the problem of having financial institutions that are "too big to fail" because their demise could wreak havoc on the broader economy.

Tuesday's announcement marks a second rejection by regulators after, after financial agencies found fault with the original bank submissions in April 2013.

Regulators have noted "some improvements" since the first round, but still point to huge flaws. The banks have until July 2015 to make "significant progress" to address the shortcomings identified.