NorthWestern Energy Announces Proposed Offering of Common Stock

NorthWestern Corporation d/b/a NorthWestern Energy http://www.northwesternenergy.com/ (NYSE: NWE) announced today that it plans to commence a registered underwritten public offering of up to $348 million of its common stock. The Company also expects to grant the underwriters a 30-day option to purchase up to an additional $52 million of the Company’s common stock.

The Company intends to use the net proceeds from this offering, together with the net proceeds of an anticipated long-term debt offering, and borrowing under our short term credit facility, as the financing for the pending acquisition of eleven hydro plants in Montana.

Credit Suisse and BofA Merrill Lynch are lead book-running managers for this offering. J.P. Morgan is joint book-running manager for this offering. Copies of the prospectus and prospectus supplement relating to the common stock offering may be obtained from the offices of 1) Credit Suisse Securities (USA) LLC at One Madison Avenue, New York, NY 10010-3629, Attn: Prospectus Department, by calling toll free 1-800-221-1037, or by e-mail at [email protected], or 2) BofA Merrill Lynch, 222 Broadway, New York, New York 10038 Attention: Prospectus Department, or by e-mailing [email protected].

A shelf registration statement relating to the securities in this offering has been filed previously with the Securities and Exchange Commission and is effective. This news release does not constitute an offer to sell or the solicitation of an offer to buy any securities in any jurisdiction to any person to whom it is unlawful to make an offer, solicitation or sale in such jurisdiction. The offering of these securities will be made only by means of a prospectus supplement and the accompanying prospectus.

About NorthWestern Energy (NYSE: NWE)

NorthWestern Energy provides electricity and natural gas in the Upper Midwest and Northwest, serving approximately 678,200 customers in Montana, South Dakota and Nebraska.