AT&T agreed Friday to pay a $23 million fine for its role in an Illinois influence-peddling scandal on the same day a federal grand jury filed a related criminal charge against former state House Speaker Mike Madigan.

Madigan, 80, and longtime friend Michael McClain, 75, were each originally charged in March with racketeering and bribery involving the utility Commonwealth Edison. Each man was additionally charged on Friday with conspiracy in a case involving AT&T Illinois. Former AT&T Illinois president Paul La Schiazza, 65, was also charged Friday with conspiracy and related counts.

The companies are accused of unlawfully paying Madigan, allegedly through McClain and others, to use his political influence on their behalf. Madigan retired last year.

The indictment Friday charges AT&T with funneling money to Madigan in exchange for a favorable vote on pending legislation in the Illinois statehouse.

AT&T admitted its guilt and agreed to pay the fine in a "deferred prosecution" agreement with the U.S. Attorney's office in Chicago. Charges will be dropped in two years if the company continues cooperating with investigators

"We hold ourselves and our contractors to the highest ethical standards," AT&T said in a statement. "We are committed to ensuring that this never happens again."

Commonwealth Edison earlier paid $200 million in exchange for a similar deferred prosecution agreement. A lobbyist, a consultant and a former Commonwealth Edison chief executive are also charged in the case.