Conrad Black says he is confident "no jury in the world" would convict on the testimony provided by the prosecution's star witness after David Radler wrapped up two weeks of gruelling testimony on Thursday.

Radler was Black's business partner for more than 30 years and agreed to testify against the former press baron in exchange for a lenient sentence.

He has spent days being called a liar by defence lawyers and accused of implicating Black and three other former executives only to secure his "sweetheart deal" with prosecutors.

"I don't think he has any credibility," Black said outside the Chicago courtroom after Radler stepped off the witness stand Thursday afternoon.

"I don't think any jury in the world would convict anybody on the basis of what he said. I repeat my long-standing view that this was never a criminal case — except possibly against him."

Radler spent his last few hours on the stand under attack from defence lawyers, who took more shots at his credibility after an aggressive attack that led to various testy and combative exchanges.

A visibly relieved Radler waved to reporters as he stepped from the stand. He didn't look at Black as he left.

No comment from prosecutors

Prosecutors said they had no comment on Black's assertions or Radler's performance, and will make their views clear during their closing arguments in the high-stakes fraud trial.

Jonathan Rosenberg, a lawyer for Hollinger International's special committee set up to investigate Black and Radler's financial dealings, followed Radler on the stand. His appearance was part of the U.S. government's attempts to persuade jurors that Black and three other executives had no approvals for the tens of millions of dollars they pocketed after the sale of company newspapers.

The so-called "non compete payments" — stemming from the sale of Canadian papers to Winnipeg-based CanWest Global Communications and U.S. papers to several U.S. buyers — are at the heart of the government's case.

Prosecutors say Black and two other former Hollinger executives — Peter Atkinson and Jack Boultbee — took millions of dollars in payments in exchange for a promise not to compete with the buyers of several Hollinger newspapers in Canada and the U.S.

Mark Kipnis, a Hollinger International lawyer based in Chicago, is accused of helping to facilitate the transactions.

Rosenberg, a New York lawyer who helped investigate shareholder concerns in 2003, said Atkinson and Boultbee both told the special committee that CanWest wasn't interested in the Hollinger executives getting the non-compete payments as a condition of closing. And both men knew the non-competes were not taxable under Canadian law.

Atkinson, Rosenberg said, "described it several times as a bonus."

"It was his impression that it didn't matter to CanWest that he receive any money."

Non-competes for Radler and Black in connection to CanWest are not in dispute, but the payments made to Atkinson and Boultbee are.

Rosenberg also interviewed Kipnis, who referred to the non-competes as "silly" and said they were really management fees.

Prosecutors also asked Rosenberg about a comment Atkinson made during a 2002 Hollinger annual meeting, when — according to Rosenberg, Atkinson said "that in his view, certain of the information was incorrectly presented."

That information related to comments Black made to shareholders about the CanWest non-competes.

Judge rules against prosecution

Judge Amy St. Eve had ruled earlier in the day that prosecutors would not be allowed to ask Rosenberg whether it was Black who made the comments or if Atkinson considered it a lie in the presence of jurors.

Before Radler left the stand Thursday, defence lawyer Ron Safer got a few parting shots at him.

Safer said earlier Thursday that Radler would have spent 71 months in jail if he did not implicate the former press baron in an alleged fraud scheme.

Safer, a lawyer for co-defendant Mark Kipnis, said Radler initially faced a jail sentence of 57 to 71 months under general guidelines in the United States if he pleaded guilty.

That sentence was reduced to a maximum of 29 months after Radler fingered Black as the organizer of a plan to divert millions of dollars from Hollinger shareholders.

"You understood that if you were found to be an organizer or leader of criminal activity the guidance range [for the sentence] would increase," Safer charged.

"You and the government reached an agreement that your sentence should be 29 months … but the only way you get the 29 months is if the prosecution makes a motion to the judge.

Nervous and annoyed

He appeared both nervous and annoyed, alternately shooting apprehensive glances at the jury and sighing and shaking his head.

"I have to say yes," he eventually conceded in a low voice.

He insisted he was telling the truth, but admitted that if there had been no others charged in the case he "presumably would have a trial."

"You wouldn't do anything to put [your plea] agreement in danger," Safer told Radler, saying he was simply repeating facts "the government gave you."

"If you do that, you'll get out [of jail] in six months," he said.

The jurors, who have regularly dozed off or entertained themselves by twirling their hair during the trial, listened attentively to the exchange, having turned in their chairs to look straight at Radler.