CHICAGO—Gov. Rod Blagojevich and his chief of staff, John Harris, were arrested Tuesday for what U.S. Attorney Patrick Fitzgerald called a “political corruption crime spreeâ€Â that allegedly included attempts to sell the U.S. Senate seat vacated by President-elect Barack Obama.

Blagojevich and Harris were named in a federal criminal complaint that alleged a wide-ranging criminal conspiracy aimed at providing financial benefits to the governor, his political fund and to his wife, first lady Patricia Blagojevich.

Blagojevich was taken into federal custody by FBI agents at his North Side home Tuesday morning—one day shy of his 52nd birthday.

The arrests dealt a tumultuous blow to Illinois government, at once raising questions about the leadership of the state and the fate of the open Senate seat—which the governor alone has the power to fill under the state constitution.

The allegations against Blagojevich provide a sharp contrast to a Democratic governor who campaigned for office promising reforms in the wake of disgraced, scandal-tainted Republican chief executive George Ryan. The complaint against Blagojevich comes little more than two years after Ryan was sentenced to six years in prison on federal corruption charges.

Lt. Gov. Pat Quinn called on Blagojevich to step aside, at least temporarily, or resign because the governor is “seriously impeded from carrying out his oath of office.â€Â

“I think he knows what he needs to do for the people,â€Â said Quinn, a Democrat.

Attorney General Lisa Madigan, who had been viewed as a likely 2010 challenger if Blagojevich sought a third term, said the governor should immediately step down. Madigan, the daughter of longtime Blagojevich nemesis House Speaker Michael Madigan, also said she was moving forward on legal issues if the governor did not resign.

Despite facing myriad federal investigations throughout his five-year tenure, Blagojevich has maintained he committed no wrongdoing. On Monday, Blagojevich said any discussions he has had were “always lawful.â€Â

The stunning, early morning arrests followed a series of Chicago Tribune stories revealing federal investigators had compiled secret recordings of the governor with the cooperation of a longtime confidant. In recent days, the focus of federal investigators expanded beyond a probe of allegations of wrongdoing involving state jobs, contracts and appointments in exchange for campaign dollars to the possibility that the Senate succession process had become tainted by pay-to-play politics.

Blagojevich and Harris were arrested simultaneously at their homes at about 6:15 a.m., according to the FBI. They were transported to FBI headquarters in Chicago. Blagojevich appeared before U.S. Magistrate Judge Nan Nolan early in the afternoon and heard the charges read against him before being released on his own recognizance.

Spurring federal investigators to act was Blagojevich̢۪s pending appointment of a Senate successor to Obama, whose resignation took effect Nov. 16. Blagojevich had said he expected to name a new senator around the end of the year.

Prosecutors said they had numerous recorded conversations of Blagojevich discussing the merits of potential candidates, including their abilities to benefit the people of Illinois as well as the financial and political benefits he and his wife could receive.

Under state law, the governor has the sole, unfettered discretion to name Obama̢۪s successor. Despite his arrest, he continues to have the naming authority and some lawmakers discussed looking for ways to wrest it from him.

Prosecutors alleged Blagojevich sought appointment as secretary of health and human services or wanted an ambassadorship in the new Obama administration, or to be placed in a lucrative union-affiliated job in exchange for appointing Valerie Jarrett, a close friend and adviser to the president-elect to the Senate seat. Jarrett eventually took herself out of the running.

Fitzgerald quoted a Blagojevich conversation in which the governor said the Senate seat is “a bleeping valuable thing. You just don’t give it away. … I’ve got this thing and it’s bleeping golden.â€Â

Obama spoke briefly about the arrest Tuesday in Chicago.

“Obviously, like the rest of the people of Illinois, I am saddened and sobered by the news that came out of the U.S. Attorney’s Office today,â€Â Obama said. “But as this is an ongoing investigation involving the governor, I don’t think it would be appropriate for me to comment on the issue at this time.â€Â

Blagojevich also was alleged to be using a favors list, made up largely of individuals and firms that have state contracts or received taxpayer benefits, from which to conduct a $2.5 million fundraising drive before year̢۪s end when a new tougher law on campaign donations, prompted by the governor̢۪s voracious fundraising, would take effect.

Blagojevich and Harris also allegedly conspired to demand the firing of Chicago Tribune editorial board members responsible for editorials critical of Blagojevich in exchange for state help with the sale of Wrigley Field, the Chicago Cubs baseball stadium owned by Tribune Co.

By Jeff Coen, Rick Pearson and David Kidwell / McClatchy Tribune