M. Spencer Green, File, Associated Press
FILE - In this April 16, 2009 file photo, Springfield, Ill., powerbroker William Cellini leaves federal court in Chicago. Jury selection is scheduled to begin Monday, Oct. 3, 2011, for Cellini, 76, who is charged with conspiring to shake down a Hollywood producer for a $1.5 million contribution to then Gov. Rod Blagojevich's campaign. It is the last major trial stemming from a nearly decade-long investigation of the former governor.

CHICAGO — The last trial stemming from the decade-long investigation of former Illinois Gov. Rod Blagojevich begins Monday when a school teacher-turned-mega millionaire faces charges of conspiring to shake down the Oscar-winning producer of "Million Dollar Baby."

William Cellini, known in his heyday as The King of Clout and the pope of Illinois politics, is due in court as jury selection gets under way. A jury could be in place by Tuesday, with attorneys delivering their opening remarks to jurors that afternoon. The trial in the same Chicago courtroom where Blagojevich was recently convicted is expected to last about three weeks.

The enigmatic Cellini, 76, a lifelong Republican who worked in the shadows of state power for nearly four decades, is accused of trying to extort producer Thomas Rosenberg for a $1.5 million campaign contribution to Blagojevich, a Democrat.

The Springfield businessman has pleaded not guilty to extortion conspiracy, attempted extortion, solicitation of a bribe and conspiracy to commit fraud and is free on $1 million bond. If convicted on all counts, he could spend more than 50 years in prison.

Blagojevich was convicted at retrial earlier this year of trying to sell or trade President Barack Obama's old Senate seat. His two trials revealed the ex-governor as charismatic but lacking discipline. He seemed to bumble his way through his job and now, at 54, is broke and about to be sentenced to prison.

Cellini is in many ways the opposite. State contacts helped him earn tens of millions from real estate, casino and even asphalt businesses, and he has held on to much of his wealth. The son of a policeman, Cellini has a reputation as savvy and meticulous and a man not to be crossed.

Prosecutors claim Cellini and his cohorts, including Blagojevich insiders Tony Rezko and Chris Kelly, planned to threaten Rosenberg's investment company with the loss of $220 million in state pension money from the $30 billion Illinois Teachers Retirement System they controlled unless he made the donation.

To lay the groundwork, prosecutors planned to tell jurors how Cellini forged ties with top-tier politicians as far back as the 1960s. The defense objected in pretrial hearings that prosecutors were trying to cast Cellini's knack for befriending the powerful in a sinister light.

Cellini is represented by some of Illinois' most sought after private lawyers, including lead attorney Dan Webb, a former U.S. attorney who also defended Blagojevich's predecessor, Republican Gov. George Ryan. Ryan is serving a 6 ½-year term at an Indiana prison on multiple corruption counts.