Federal agents are investigating real estate deals involving Gov. Rod Blagojevich's wife as part of a three-year corruption probe into allegations of favoritism and fraud within his administration.

Several federal sources familiar with the inquiry confirm that agents are interested in hundreds of thousands of dollars in real estate commissions Patricia Blagojevich has earned in recent years as a real estate broker for political supporters, fundraisers and state contractors.

One real estate agent told the Tribune that FBI agents contacted her in recent weeks with questions about her dealings with Patricia Blagojevich in a $3.2 million sale of a Gold Coast home in 2004. The seller was an investment banker and generous contributor to the governor's campaign fund who hired the first lady as his second agent on the deal.

It is the latest in a series of real estate deals disclosed by the Tribune in which the governor's wife received commissions from politically connected clients. Most of those deals involved people seeking favor from the government her husband leads.

Neither the governor nor his wife has been accused of any wrongdoing.

But the revelation is the strongest indication yet that the federal investigation into allegations that state business, jobs and other favors were traded for campaign donations reaches beyond the governor's public administration and into his family's finances.

The governor's chief spokeswoman described the first lady as an ethical businesswoman who has been a licensed real estate broker and appraiser for more than 15 years.

"No one -- and I mean no one -- has told us that she is under investigation, and there's no reason she would be," said Abby Ottenhoff in an e-mailed response to questions Thursday. "She has done nothing wrong.

"But what is really sad is that someone has resorted to malicious rumors and innuendo to attack the governor's wife. This has sunk to an outrageous new low."

Randall Samborn, a spokesman for the U.S. attorney's office, declined to comment.

In an interview this week with the Tribune, real estate agent Mary Bennett said FBI agents contacted her firm's attorneys requesting she sit down with them. She said agents wanted her to explain why she agreed to add Patricia Blagojevich as a second agent in the 2004 sale of a home in the 1200 block of North Astor Street.

Bennett said she included Patricia Blagojevich at the request of the owner, John H. Simpson, an investment banker who has donated $97,000 to Gov. Blagojevich's campaign fund since 2002.

"I figured the seller wanted to throw her a little business," said Bennett, who was the agent when Simpson bought the house in 1997. "Half a listing is better than none at all, so that's what I did.

"I had sold the house before, I figured I could sell it quick -- so I agreed," said Bennett, a longtime real estate agent in the toney, historic neighborhood.

The 2004 real estate listing shows Patricia Blagojevich as co-listing agent. Bennett said Patricia Blagojevich collected a quarter of the 4 percent commission on the sale -- about $32,000.

Simpson, reached by telephone at his California office, declined to comment. Before moving, he worked at a Chicago investment firm that also used to employ U.S. Rep. Rahm Emanuel (D-Ill.), a close ally of Gov. Blagojevich's and the man who succeeded the governor in his seat in Congress. A check of state records indicates that neither Simpson nor his firm has any state contracts.

JoAnn Turnquist, who with her husband bought the home from Simpson, said she had not been contacted by federal agents. She said she met Patricia Blagojevich during the home inspection.

Bennett said that because of her firm's rules on contact with law enforcement, the FBI agents requested an interview through her firm's lawyer, Richard Perna. He declined to comment on the FBI contact.

Bennett canceled her first appointment with the FBI because of business commitments, she said. She has yet to reschedule the interview.