CHICAGO (AP) — A class-action lawsuit filed in Cook County seeks $150 million in refunds from ComEd for rate increases and benefits the utility received from Illinois as part of an alleged bribery scheme.

The lawsuit was filed Monday by three individuals and a Chicago-based company.

Prosecutors have said ComEd agreed to pay $200 million to resolve a federal criminal investigation that implicates Illinois House Speaker Madigan, who hasn’t been charged with wrongdoing. The lawsuit alleges “rampant and widespread corruption” that “deprived ratepayers of vast sums of money.”

ComEd officials say the company’s lobbying practices have been reformed.