Conrad Black, the former Hollinger International chairman serving a 6½-year prison term for stealing from the company, asked the judge who sentenced him for bail while the US Supreme Court reviews his conviction.

Black’s lawyers, in papers filed yesterday with US District Judge Amy St. Eve in Chicago, said the high court’s May decision to hear a challenge to his 2007 conviction for mail fraud indicates there is a “substantial question” concerning his guilt, raising the possibility of a new trial or reduced prison term.