Conrad Black has applied for bail with the 7th Circuit Court of Appeals in Chicago.

In a filing late Tuesday, lawyers for the Montreal-born media baron argued that he should be released immediately in the wake of a U.S. Supreme Court ruling in late June that set aside his fraud convictions.

Convicted newspaper mogul Conrad Black has applied to be released on bail while the court that originally upheld his fraud conviction considers the Supreme Court's decision on his case. (M. Spencer Green/Associated Press)

"Mr. Black has been in custody for over two years," his lawyer, Miguel Estrada, argued in a 26-page filing with the 7th Circuit Court of Appeals in Chicago on Tuesday. "The additional time he spends in prison between now and a favourable ruling can never be returned to him. Mr. Black should be granted release pending appeal."

America's top court set aside his fraud convictions in June, but Black's conviction for obstruction of justice remains in place. The appeal court will now have a hearing on his bail request while it decides whether to overturn his fraud convictions in light of the Supreme Court's decision.

It is not yet known when that might happen; appeals courts are unaccustomed to dealing with bail requests, so the process is expected to take weeks, legal experts say.

The 7th Circuit Court is the same one that first denied Black's request for bail after he was convicted, along with three other Hollinger executives in 2007, of defrauding $6.1 million US from the company.

He was originally accused of pilfering more than $60 million US.

"The circumstances surrounding the instant bail application differ quite significantly from those that existed when this court denied Mr. Black's application for bail pending his original appeal," Estrada wrote.

That same court has already twice rejected Black's attempts at having his conviction overturned.