WASHINGTON (Reuters) - The White House will likely make a decision by June on whether it will release some classified material withheld from the public 9/11 Commission Report, a former U.S. senator who co-chaired the congressional inquiry into the attacks said on Sunday. The withheld section of the official report on the 2001 attacks is central to a dispute over whether Americans should be able to sue the Saudi Arabian government for damages. The Office of the U.S. Director of National Intelligence is reviewing the material to see whether it can be declassified.     Former Sen. Bob Graham, a Florida Democrat, has been pressing for the release of the information and said that it may shed light on the financial backers for 19 hijackers who killed nearly 3,000 people on Sept 11, 2001. Graham told NBC’s Meet the Press that he believed that some of the withheld classified material could soon be released. “The president’s staff at least has said that they will make a decision by June, and I hope that decision is to honor the American people and make it available,” Graham said. Representative Adam Schiff, the top Democrat on the House of Representatives Intelligence Committee, said last week that he also supported releasing the material. “The release of these pages will not end debate over the issue, but it will quiet rumors over their contents,” Representative Adam Schiff said in a statement. “As is often the case, the reality is less damaging than the uncertainty.” 