Ally, the former financial arm of General Motors, is still majority owned by the government because it hasn't paid back its crisis-era bailout loans.

WSJ: Fed: JPMorgan, Goldman need better capital plans

Government-controlled Ally Financial, the rescued former finance arm of General Motors, was the only bank to fail the test of capital strength.

BBC: Ally Financial sign

This follows on from the Fed's annual "stress tests" of the banks' financial health, which it said that all the 18 biggest US lenders had passed except for Ally, the government-controlled rescued former finance arm of carmaker General Motors.

BBC: Federal Reserve approves most bank capital plans