By Colin Kellaher 



  Exelon Corp. on Friday said its ComEd unit would pay $200 million as part of an agreement to resolve a U.S. Justice Department investigation into the unit's lobbying practices in Illinois. 


  Under a three-year deferred prosecution agreement, ComEd also agreed to the government's filing of a single charge that will be dismissed if the unit abides by all terms, Exelon said, adding that the fine won't be recovered in rates or charged to customers. 


  Exelon said it acted swiftly to investigate when it learned about the inappropriate lobbying conduct at the unit, and that it determined that a small number of senior ComEd employees and outside contractors were responsible. 


  "Since then, we have taken robust action to aggressively identify and address deficiencies, including enhancing our compliance governance and our lobbying policies," the company said. 


  Exelon noted that the conduct at issue relates only to ComEd, and that the agreement doesn't contain any allegation of misconduct by the parent company. 


  While the deal resolves the government's investigation into both ComEd and Exelon, a related U.S. Securities and Exchange Commission investigation, as well as civil lawsuits, remain pending, Exelon said. 


  Write to Colin Kellaher at colin.kellaher@wsj.com