CHICAGO - U.S. Attorney Patrick Fitzgerald wants to release tape recordings of Illinois Gov. Rod R. Blagojevich discussing campaign contributions with a lobbyist to a panel of state lawmakers considering his impeachment.

Four intercepted calls from Fitzgerald's political-corruption probe of Blagojevich, a Democrat, should be released in redacted form to the Illinois House impeachment committee, prosecutors said in a filing yesterday in federal court in Chicago.

Fitzgerald said last Tuesday that he would not provide affidavits, fund-raising lists or other materials to the committee because it might compromise his own inquiry into political corruption. The panel had asked for the recordings.

But in yesterday's filing, he said: "Disclosure of the calls by themselves would not interfere with the ongoing criminal investigation."

Blagojevich, 52, was arrested Dec. 9 at his home in Chicago and charged with solicitation of bribery for trying to sell the Senate seat vacated by President-elect Barack Obama for as much as $1.5 million or using his appointment power to secure an ambassadorship, a position in Obama's cabinet, or a lucrative job running a nonprofit group. He was also accused of taking campaign contributions in exchange for other official acts.

Fitzgerald's move came as Blagojevich attorney Ed Genson argued that he had been forced to fight "shadows" in trying to defend the governor - the panel's refusal to call his witnesses, unchallenged allegations in a federal criminal complaint, and a lack of standards to remove an elected official from office.

Genson previously described the tape recordings as "illegal." Yesterday, he said he wanted to review Fitzgerald's filing before determining whether it was appropriate for transcripts of the recordings to be used. He also said portions of the recordings, filed along with the criminal charges, showed "unfortunate talk" but nothing illegal.

Speaking to the committee weighing Blagojevich's impeachment, Genson alleged that the panel's witnesses "have not shown impeachable conduct."

"We're fighting shadows here. We're fighting unnamed people," Genson said. He contended that "part of the shadow" was Fitzgerald's investigation. "What [federal prosecutors] are saying is they won't tell us anything, but we are responsible or should come in and deny it, and give them a forecast of what our case is. . . . Until the United States government tells us what he's charged with, we choose not to talk about it."

Court-approved wiretaps intercepted Blagojevich calls in November and December with lobbyists, fund-raisers, staffers, and John Harris, his chief of staff, who was also charged.

On the calls Fitzgerald seeks to release, which were made last month from the cell phone of "Lobbyist 1," Blagojevich discussed with a fund-raiser and a lobbyist when he would sign a bill giving casino revenue to the horse-racing industry, prosecutors said. The lobbyist represented a contributor whom Blagojevich's fund-raisers were soliciting for $100,000, according to court records.

Blagojevich told the lobbyist that he would call the contributor, who had not given money, "so we can get together and start picking some dates to do a bill signing," according to an FBI affidavit.

Under federal law, people whose phone calls were monitored can request that the contents of the intercepted calls be suppressed. A hearing is set for Monday.

This article contains information from the Chicago Tribune.