CHICAGO — Another domino has fallen in the corruption case against former Illinois Gov. Rod Blagojevich.

Alonzo "Lon" Monk, one of the governor's closest friends and advisers, pleaded guilty Tuesday and agreed to aid prosecutors in their attempt to convict the former governor. In exchange, he faces a recommended sentence of two years in prison.

If his plea agreement is any indication, Monk — a former chief of staff to the governor and his two-time campaign manager — could be a valuable witness.

His 31-page plea agreement provides the most damning detail yet about meetings between Blagojevich and his three closest confidants — Monk, Antoin "Tony" Rezko and the late Christopher Kelly.

The indictment against Blagojevich last spring alleged that, even before Blagojevich was first elected governor in 2002, the four had discussed ways to profit from public corruption.

Monk's plea agreement states that Rezko typically led the discussions, and most of the ideas were intended to bring in hundreds of thousands of dollars.

Monk disclosed that Blagojevich and others talked about how to personally benefit from a real estate development Rezko had planned at Clark Street and Roosevelt Road in Chicago.

"Rezko talked about different ways that defendant, Blagojevich and Kelly could benefit from the (project), such as by having Blagojevich's wife (Patricia) work on marketing the project or by allowing defendant to work on the project after (he) left state government," the plea agreement said.

The four also planned to make money through the refinancing of $10 billion in pension obligation bonds, which the state contemplated in 2003, the document states.

Monk allegedly was involved in deciding which investment firm would be chosen to be lead underwriter on the deal, with Rezko and Kelly pushing a particular firm.

That arrangement was mentioned in the Blagojevich indictment in the spring, and the Chicago Tribune has identified the company as Bear Stearns, working with lobbyist Robert Kjellander, who has never been charged with wrongdoing.