Wisconsin Energy Corp. will pay cash and stock valuing Integrys Energy Inc. at about $5.8 billion. The rest of the $9.1 billion deal includes assumed debt. Integrys is the second utility company with headquarters in Chicago to go in the last three years. Integrys is the parent company of Peoples Gas, which serves the city of Chicago, and North Shore Gas, which delivers gas to the North Shore suburbs. The Illinois Commerce Commission still has to approve the deal.