Michigan PSC Approves Wisconsin Energy Acquisition of

CHICAGO, IL--(Marketwired - Apr 23, 2015) - The Michigan Public Service Commission (MPSC) today approved the acquisition of Integrys Energy Group, Inc. ( NYSE : TEG ) by Wisconsin Energy Corp. ( NYSE : WEC ). The companies announced the proposed acquisition in June of 2014.

"We're pleased that the key groups were able to reach an agreement satisfactory to all parties that ultimately resulted in the MPSC written order for approval," said Integrys Energy Group Chairman and Chief Executive Officer Charles Schrock. "This action brings us another step closer to completing the transaction with Wisconsin Energy."

Still pending are filing approvals from the Public Service Commission of Wisconsin, Minnesota Public Utilities Commission and Illinois Commerce Commission.

About Integrys Energy Group, Inc. Integrys Energy Group is a diversified energy holding company with regulated natural gas and electric utility operations (serving customers in Illinois, Michigan, Minnesota, and Wisconsin), an approximate 34% equity ownership interest in American Transmission Company (a federally regulated electric transmission company operating in Wisconsin, Michigan, Minnesota, and Illinois), and nonregulated energy operations. More information is available at www.integrysgroup.com .

Additional Information and Where to Find It In connection with the proposed merger transaction between Wisconsin Energy Corporation ("Wisconsin Energy") and Integrys Energy Group, Inc. ("Integrys"), Wisconsin Energy filed with the Securities and Exchange Commission (the "SEC") a registration statement on Form S-4 that includes a joint proxy statement/prospectus for the shareholders of Wisconsin Energy and Integrys. The registration statement was declared effective by the SEC on October 6, 2014. Each of Wisconsin Energy and Integrys mailed the joint proxy statement/prospectus to their respective shareholders on or around October 21, 2014 and filed other documents regarding the proposed merger transaction with the SEC. Integrys urges investors and shareholders to read the joint proxy statement/prospectus, as well as other documents filed with the SEC, because they contain important information. Investors and security holders may receive the registration statement containing the joint proxy statement/prospectus and other documents free of charge at the SEC's web site, http://www.sec.gov , from Wisconsin Energy at Corporate Secretary, 231 W. Michigan St. P.O. Box 1331 Milwaukee, WI 53201, or from Integrys at Integrys Energy Group, Inc., Investor Relations, 200 East Randolph Street, 23rd Floor, Chicago, IL 60601.

Forward-Looking Statements This communication contains certain forward-looking statements with respect to the financial condition, results of operations and business of Integrys and the combined businesses of Integrys and Wisconsin Energy and certain plans and objectives of Integrys with respect thereto, including the expected benefits of the proposed merger transaction. These forward-looking statements can be identified by the fact that they do not relate only to historical or current facts. Forward-looking statements often use words such as "anticipate," "target," "expect," "estimate," "intend," "plan," "goal," "believe," "hope," "aim," "continue," "will," "may," "would," "could" or "should" or other words of similar meaning or the negative thereof. There are several factors which could cause actual plans and results to differ materially from those expressed or implied in forward-looking statements. Such factors include, but are not limited to, the expected closing date of the proposed merger transaction; the possibility that the expected synergies and value creation from the proposed merger transaction will not be realized, or will not be realized within the expected time period; the risk that the businesses will not be integrated successfully; disruption from the proposed merger transaction making it more difficult to maintain business and operational relationships; the risk that unexpected costs will be incurred; changes in economic conditions, political conditions, trade protection measures, licensing requirements and tax matters; the possibility that the proposed merger transaction does not close, including, but not limited to, due to the failure to satisfy the closing conditions; the risk that financing for the proposed merger transaction may not be available on favorable terms. These forward-looking statements are based on numerous assumptions and assessments made by Integrys in light of its experience and perception of historical trends, current conditions, business strategies, operating environment, future developments and other factors that it believes appropriate. By their nature, forward-looking statements involve known and unknown risks and uncertainties because they relate to events and depend on circumstances that will occur in the future. The factors described in the context of such forward-looking statements in this communication could cause actual results, performance or achievements, industry results and developments to differ materially from those expressed in or implied by such forward-looking statements. Although it is believed that the expectations reflected in such forward-looking statements are reasonable, no assurance can be given that such expectations will prove to have been correct and persons reading this communication are therefore cautioned not to place undue reliance on these forward-looking statements which speak only as at the date of this communication. Integrys does not assume any obligation to update the information contained in this communication (whether as a result of new information, future events or otherwise), except as required by applicable law. A further list and description of risks and uncertainties at Integrys can be found in Integrys's Annual Report on Form 10-K for the fiscal year ended December 31, 2014 and in its reports filed on Form 10-Q and Form 8-K.