The U.S. Federal Reserve won a delay of a federal judge's order that it reveal the names of the banks that have participated in its emergency lending programs and the sums they received.

Chief Judge Loretta Preska of the U.S. District Court in Manhattan stayed her August 24 order in favor of Bloomberg News, which had sought the information under the federal Freedom of Information Act, so that the central bank could appeal.

The Fed's board of governors has worried that disclosure would stigmatize the participating banks, threatening both them and the U.S. economy.

It argued disclosure threatened irreparable harm to these institutions and to the board's ability to effectively manage the current, and any future, financial crisis.

The case and a similar one involving News Corp's Fox News Network LLC raise the issue of how much the public has a right to know about how the government is bailing out a troubled financial system.

The Fed was not immediately available for comment.

Preska directed the Fed's board of governors to file a notice of appeal and an emergency stay application with the 2nd U.S. Circuit Court of Appeals.

She also said Bloomberg will not, for now, insist on a search of official files at the Federal Reserve Bank of New York, after the central bank's representation that a search would likely be fruitless.

The case arose when two Bloomberg reporters submitted FOIA requests about actions the Fed took to shore up the financial system in 2007 and early 2008, including an expansion of lending programs and the sale of Bear Stearns Cos to JPMorgan Chase & Co .

The case is: Bloomberg LP v. Board of Governors of the Federal Reserve System, U.S. District Court, Southern District of New York (Manhattan), No. 08-9595.

(Reporting by Jonathan Stempel, editing by Leslie Gevirtz)