WASHINGTON, June 28 (Reuters) - Big U.S. banks sailed through the Federal Reserve's annual health check on Wednesday, in a vote of confidence for the sector that is still recovering from turmoil earlier this year and faces an uncertain economic outlook.

The Fed's "stress test" exercise showed lenders, including JPMorgan Chase, Bank of America, Citigroup , Wells Fargo, Morgan Stanley and Goldman Sachs, have enough capital to weather a severe economic slump, paving the way for them to issue share buybacks and dividends.

The 23 banks tested, which all have more than $100 billion in assets each, would suffer a combined $541 billion in losses under the Fed's severe downturn scenario, but would still have over twice the amount of capital required under its rules.

(Reporting by Pete Schroeder; editing by Michelle Price and Deepa Babington)