Christopher Kelly, one of Gov. Rod Blagojevich's most trusted advisers and fundraisers, has decided to plead guilty, court records show, while negotiations appear to be on again for the cooperation of Antoin "Tony" Rezko, another Blagojevich confidant, in the federal probe.

U.S. District Judge Elaine Bucklo, saying in court papers that she acted at the request of lawyers in the case, set a hearing for Jan. 16 for Kelly's change of plea. Kelly was scheduled to go on trial on Jan. 20 on tax fraud charges.

There were no immediate signals that Kelly planned to cooperate with prosecutors against Blagojevich.

Also Tuesday, Rezko's sentencing was indefinitely delayed, signaling again that he is negotiating with the government for his possible cooperation against Blagojevich. Rezko, who was convicted in June of scheming to extort firms seeking state business, had recently become frustrated at being held in solitary confinement in a Loop federal jail. The FBI disclosed last week in court papers that Rezko had provided incriminating evidence against the governor since his trial.

—Jeff Coen