Filed by Integrys Energy Group, Inc.
Pursuant to Rule 425 under the Securities Act of 1933

Subject Company: Integrys Energy Group, Inc.
Commission File No.: 1-11337


On June 12, 2015, Integrys Energy Group, Inc. posted the following announcement to the Integrys internal transaction website:

Minnesota commission votes to approve Integrys acquisition

The Minnesota Public Utilities Commission (MPUC) today voted to approve Wisconsin Energy Corporation’s proposed acquisition of Integrys Energy Group Inc. A final written order is expected in the next several weeks. Today’s vote represents another positive and important step in the process of finalizing the acquisition of Integrys.

The acquisition was previously approved by the Federal Energy Regulatory Commission (FERC) on April 7, Michigan Public Service Commission (MPSC) on April 23, and Public Service Commission of Wisconsin (PSCW) on May 21.

The Administrative Law Judge’s proposed order in Illinois recommends approval of the acquisition and still appears to be on track for an Illinois Commerce Commission (ICC) vote on or before the statutory deadline of July 6.

If all regulatory approvals are received, close of the transaction is anticipated by the end of the summer.

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, 2013 and in its reports filed on Form 10-Q and Form 8-K.