By Warren Strobel and Mark Hosenball WASHINGTON (Reuters) – A White House-appointed panel on Wednesday proposed curbs on some key National Security Agency surveillance operations, recommending limits on a program to collect records of billions of telephone calls and new tests before Washington spies on foreign leaders. Among the panels proposals, made in the wake of revelations by former NSA contractor Edward Snowden, the most contentious may be its recommendation that the eavesdropping agency halt bulk collection of the phone call records, known as metadata. Instead, it said, those records should be held by telecommunications providers or a private third party. In a further limitation, the U.S. government would need an order from the Foreign Intelligence Surveillance Court for each search of the data. We dont see the need for the government to be retaining that data, said Richard Clarke, a member of the panel and a former White House counterterrorism adviser.