The expanded company now serves 4.4 million customers in Wisconsin, Illinois, Michigan and Minnesota.

Several energy companies reported their second-quarter earnings results last week.

Ameren, Wisconsin Energy and Xcel Energy announced their first-quarter earnings results.

Michigan regulators on Thursday approved Wisconsin Energy Corp.’s $9.1 billion acquisition of Illinois-based Integrys Energy — with the condition that the merged companies continue to operate the Presque Isle Power Plant in Michigan’s Upper Peninsula.

Wisconsin Energy Corp. profits fell 16% in the fourth quarter on warmer weather and $6 million in costs related to its proposed acquisition of Integrys.