A federal appeals court yesterday denied a request by former D.C. mayor Marion Barry to send his case back to U.S. District Judge Thomas Penfield Jackson so Barry's attorneys could introduce evidence alleging that Jackson was biased against Barry.

The appeals court did, however, agree to give Barry's attorneys an additional two weeks to prepare an appeal of the former mayor's conviction for cocaine possession. The brief had been due yesterday.

Barry's attorneys said in a motion last week that Jackson's bias against Barry was revealed in remarks Jackson delivered Oct. 30, four days after the judge sentenced Barry to six months in prison and fined him $5,000.

In a speech at Harvard University, Jackson said he thought the government's case against Barry was the strongest he had seen, and he said he thought Barry was guilty of many of the charges on which the jury was unable to reach a verdict.

Prosecutors objected to the motion, saying there was nothing in Jackson's remarks to indicate he had formed his opinion about Barry on anything other than evidence presented at the 10-week trial.

If the case had been sent back to Jackson, Barry's attorneys had hoped to introduce evidence of Jackson's alleged bias so it could be reviewed as part of Barry's appeal. Federal law allows appeals courts to consider only evidence established before the trial court.

Barry was convicted of a single cocaine possession charge and acquitted of a second. The jury was unable to reach a verdict on 12 remaining charges. U.S. Attorney Jay B. Stephens has dropped those 12 charges.

Oral arguments in the case are set for April 30.