CHICAGO — A prominent fundraiser for Senator Obama and Governor Blagojevich of Illinois was convicted today of fraud and money laundering after a high-profile federal trial provided an unusually detailed glimpse of the pay-to-play politics that has made Illinois infamous.

Antoin Rezko, 52, showed no emotion as the jury delivered a mixed verdict that found him guilty of scheming with the government’s star witness to get kickbacks out of money management firms wanting state business, but acquitted him of charges that included attempted extortion.

The jury delivered its guilty verdict on 16 of 24 counts after a nine-week trial.

Rezko has known Mr. Obama since he entered politics and was involved in a 2005 real estate deal with the Democratic presidential candidate, although testimony barely touched on their relationship. Most of the focus was on shakedowns prosecutors said Mr. Rezko arranged when he was a top adviser to Mr. Blagojevich.

Neither Mr. Blagojevich nor Mr. Obama has been accused of wrongdoing.

Rezko’s defense attorneys maintained that the government had little evidence tying him to corruption and that the star witness, admitted a political fixer, Stuart P. Levine, was not credible because years of drug use had damaged his memory.

Levine was a member of a state board that decided which hospitals got built and was on a panel that decided which investment firms got allocations from a $40 billion fund that pays the pensions of retired teachers.

Levine testified that Rezko, drawing on the political clout he developed as a Blagojevich fundraiser, stacked both boards with members who could be relied upon to follow orders when big-money decisions came up. Prosecutors said he used that clout to shake down companies and individuals hoping for state business for $7 million in kickbacks.

While Mr. Obama’s name rarely surfaced during testimony, the case drew attention to Mr. Obama’s relationship with Rezko, a man Senator Clinton derided in one televised debate as a “slum landlord.”

Rezko, a real estate developer and fast-food entrepreneur, had been friendly with Mr. Obama for years, even offering him a job after Mr. Obama finished law school. Mr. Obama turned down the offer, but a political friendship developed.

Rezko donated more than $21,000 to Mr. Obama and raised far more for his campaigns in Illinois, though not his presidential bid.

He also advised Mr. Obama on the purchase of a new Chicago home and, in his wife’s name, purchased a vacant lot next to the new Obama home at the same time from a couple who insisted on selling both pieces of property simultaneously. The purchase raised questions about the extent of his help.

The charges against Rezko had nothing to do with Mr. Obama, who has donated $150,000 in Rezko-related contributions to charity.

Rezko, 52, was charged with scheming with Levine to split a $1.5 million kickback from a contractor who wanted to build a hospital in northern Illinois and to shake down money management firms wanting to invest in the teacher pension fund.

Rezko denied he had anything to do with such a scheme.

Rezko attorneys claimed that once FBI wiretaps picked up Levine talking about payoffs and other corruption he needed to provide federal prosecutors with a “big fish” like Rezko in order to get a deal and avoid a possible life sentence.

Levine did make a deal with prosecutors under which instead of life he will probably get a 5½-year prison sentence and forfeit $5 million. He admitted on the stand that for 30 years he attended twice-a-month marathon drug parties, where he shared drugs including cocaine and crystal methamphetamine with male companions.

Rezko attorneys said Levine’s brain had been so badly damaged that he couldn’t recall what Rezko had said and done years ago.