CHICAGO - Conrad Black's lawyers are trying to postpone his Nov. 30 sentencing date, saying they need "short extension'' to prepare objections to pre-sentence reports.

Black, once the head of one of the world's biggest media empires, is to be sentenced in Chicago following criminal convictions for fraud and obstruction of justice.

On Monday, he lost a bid for a new federal fraud trial, which cleared the way for sentencing and meant Black's last remaining option for fighting the chances would be a post-setencing appeal.

His lawyers now say they more time to file objections to the pre-sentence report -- or PSR -- expected Tuesday, and a later sentencing date. Under the current schedule, the defendants need to file objections to the PSRs by Nov. 20.

"Defendant Black seeks a short extension of the latter two dates to permit his chief sentencing counsel, Jeffrey Steinback, who did not participate in the trial, additional time to review the PSR before filing written objections to it, and to prepare for the sentencing hearing,'' they said in documents filed with a Chicago court Thursday night.

"In light of the legal and factual complexities of this case and his sentencing counsel's relatively recent involvement in the matter, defendant Black believes the short extension of time is needed to ensure that counsel has a sufficient opportunity to review ad respond to the PSR and prepare for the sentencing hearing.''

They're seeking 14 days after receipt of the PSR to file his objections, to Nov. 27, "but ask for only 21 days (rather than the requisite 35) after receipt of the PSR before the sentencing hearing is held.''

If approved, that means Black and his three co-defendants -- also convicted of fraud -- could be sentenced in mid-Decemeber.

Black, Peter Atklinson, Jack Boultbee and Mark Kipnis were convicted July 13 of three mail fraud counts for pocketing millions of dollars prosecutors said belonged to shareholders in his Hollinger International newspaper empire. Black was also convicted of spiriting boxes of documents out of his Toronto offices even though he knew federal prosecutors wanted them.

One count against Kipnis was dropped earlier this week.

Black, who gave up his Canadian citizenship in 2001 to become a member of Britain's House of Lords, was freed on bail pending sentencing on November 30, but told to stay in Chicago or in Palm Beach, Fla., where he owns a home.

Black's lawyers will present their arguments for a continuance to Judge Amy St. Eve on Thursday.