MDU Resources Group, Inc. (NYSE:MDU) announced today that it acquired Quality Concrete & Materials Co., Ltd., a ready-mix concrete and materials supplier headquartered in Beaumont, Texas, on Sept. 5.

Quality will become part of Knife River Corporation, the construction materials and mining subsidiary of MDU Resources. Financial details of the acquisition were not disclosed. MDU Resources anticipates the acquisition will be accretive to 2007 earnings per share.

“We are pleased to announce our expansion into the Southeast Texas market through the acquisition of Quality Concrete & Materials,” said Terry D. Hildestad, president and chief executive officer of MDU Resources. “Quality’s strong market presence in an area that is experiencing robust industrial and commercial growth will be of great benefit to our construction materials business.”

Quality operates 10 ready-mix concrete plants, two material distribution yards and three pug mills throughout Southeast and Central Texas. In total, it produces in excess of 400,000 cubic yards of ready-mix per year, and it distributes between 1 million to 2 million tons of aggregates per year for internal and third-party use through its material yards. Revenues from its operations total nearly $50 million annually.

“Quality is an excellent addition to Knife River,” said William Schneider, president and chief executive officer of Knife River. “It is a profitable and well-managed company and it reinforces our strategic commitment to grow our materials business. We are excited to welcome Doug Almond and the 125-plus employees of Quality to the Knife River family.”

Doug Almond, founder and president of Quality, will continue to lead the company, which will now operate under the Knife River brand as Knife River – East Texas Division. Knife River’s South Region includes operations in Waco, Beaumont, Bridge City, Bryan, Cameron, College Station, Evadale, Hillsboro, Jasper, Port Arthur, Rockdale and Woodville, Texas.

The information in this release includes forward-looking statements, including statements by the president and chief executive officer of MDU Resources and the president and chief executive officer of Knife River, as well as the statement with respect to the anticipated effect of the transaction upon earnings per share, within the meaning of Section 21E of the Securities Exchange Act of 1934. Although the company believes that its expectations are based on reasonable assumptions, actual results may differ materially. Important factors that could cause actual results to differ materially from those in the forward-looking statements include the ability to effectively integrate the operations. For a discussion of other important factors that could cause actual results to differ, refer to Item 1A – Risk Factors in MDU Resources’ most recent Form 10-K and Form 10-Q.

MDU Resources Group, Inc., a member of the S&P MidCap 400 index, provides value-added natural resource products and related services that are essential to energy and transportation infrastructure, operating in three core lines of business; Energy, Construction Materials and Utility Resources. MDU Resources includes natural gas and oil production, natural gas pipelines and energy services, construction materials and mining, construction services, and electric and natural gas utilities. For more information about MDU Resources, see the company's Web site at www.mdu.com or contact the Investor Relations Department at investor@mduresources.com.

Contacts:
 
  Financial: 
     Vernon A. Raile
     Executive Vice President, Treasurer and Chief Financial Officer
     (701) 530-1003

     Phyllis A. Rittenbach
     Director of Investor Relations
     (701) 530-1057

Media: 
     Rick Matteson
     Director of Communications and Public Relations
     (701) 530-1700

     Art Thompson
     Senior Public Relations Representative
     (701) 530-1054