UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K Current Report PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported) September 9, 2003 MDU Resources Group, Inc. (Exact name of registrant as specified in its charter) Delaware 1-3480 41-0423660 (State or other jurisdiction (Commission (I.R.S. Employer of incorporation) File Number) Identification No.) Schuchart Building 918 East Divide Avenue P.O. Box 5650 Bismarck, North Dakota 58506-5650 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code (701) 222-7900 Item 5. Other Events and Regulation FD Disclosure. MDU Resources Group, Inc.'s press release regarding earnings guidance for 2003 and 2004 is attached to this Form 8-K as Exhibit 99 and incorporated herein by reference. Item 7. Financial Statements and Exhibits. (c) Exhibits. Exhibit 99 - Press release issued September 9, 2003 regarding earnings guidance for 2003 and 2004. SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. MDU RESOURCES GROUP, INC. Date September 10, 2003 BY /s/ Vernon A. Raile Vernon A. Raile Senior Vice President and Chief Accounting Officer EXHIBIT INDEX Exhibit Number Description of Exhibit 99 Press release issued September 9, 2003 regarding earnings guidance for 2003 and 2004.