The U.S. Supreme Court on Thursday set aside three fraud convictions against Montreal-born Conrad Black and sent his case back to a lower court.

The jailed former media baron's conviction for obstruction of justice remains in place.

Former media baron Conrad Black has had partial success petitioning the U.S. Supreme Court for a review of his convictions for fraud and obstruction of justice. (M. Spencer Green/Associated Press)

One of Black's lawyers, Miguel Estrada, says despite his remaining conviction, the legal team will move to have Black released on bail within days. He also said Black is "delighted" with the court's decision.

"It's somewhat likely [that he'll get bail,]" said Stewart Gerson, a former assistant U.S. attorney specializing in criminal prosecutions. "It's certainly more likely now."

"My guess is that he may well be confined to the U.S. If he is released, it will be under very strict circumstances."

Black's lawyers had challenged the "honest services" fraud law, a contentious act that critics argue is too vague and has been used to make a crime out of mistakes, minor transgressions and ethical violations.

The 28-word law makes it illegal for officials, executives, employees and others to scheme to deprive those they serve and possibly others of "the intangible right to honest services." The concept crept into the legal lexicon in the 1980s, when the U.S. Congress amended fraud statutes.

During sessions in December, Justice Stephen Breyer said he worried the Obama administration's interpretation of the law makes criminals out of vast numbers of U.S. workers, including possibly employees who read a daily horse racing newspaper on the job, or send a personal email from a work computer.

On Thursday, the Supreme Court ruled that, constitutionally, the honest services law can be applied only to cases involving outright bribery or kickbacks. Since that does not apply in Black's case, essentially, the court said he can't be convicted under that provision.

The law has been central in several high-profile white-collar criminal proceedings in recent years, including that of former Enron CEO Jeffrey Skilling. In a related ruling, the Supreme Court on Thursday set aside Skilling's convictions on similar charges.

Black is more than two years into his 6½-year sentence in a Florida prison for fraud and obstruction of justice.

He was convicted in Chicago in 2007 of a $6.1-million fraud and of obstruction of justice related to his eight-year spell as head of Hollinger International Inc.

In legal terminology, the court has "vacated" his fraud convictions based on improper use of the honest services law — essentially, voiding the previous court decision.

Black's case now goes back to the 7th circuit Court of Appeals in Chicago, which upheld his original conviction.

Black is now in an interesting legal limbo in that the only conviction he's behind bars for is obstruction of justice. His lawyers argue he never would have been convicted of obstructing justice were it not for the now-vacated decision that he was guilty of fraud.

"Mr. Black was accused of trying to hide a crime, but we know that was not a crime according to what the Supreme Court has told us," Estrada said. "[His conviction] relied on something being fraud that isn't fraud."