MDU Resources Group Inc., a North Dakota-based electric utility, has purchased two more electrical contracting firms, in the continuing expansion of the utility construction segment of its diverse market interests.

With the purchases of Bell Electrical Contractors Inc., St. Louis, and Oregon Electric Construction, Portland, Ore., the Bismark, N.D.-based utility corporation will add $140 million in sales and increase its coverage of the Pacific Northwest and the Midwest.

Bell Electrical Contractors Inc., a 27-year-old electrical contracting firm with 50 nonbargaining employees, 200 union employees and annual revenues of about $40 million, focuses on commercial, industrial and institutional electrical work, as well as well as communications engineering, design and construction.

Bell Electrical will become part of MDU Resources' Utility Services Inc. subsidiary. Utility Services Inc. (USI), also based in North Dakota, is an infrastructure construction company specializing in electric, natural gas and telecommunications utility construction as well as interior industrial electrical, exterior lighting and traffic signalization. USI operates throughout most of the United States.

Ron Tipton, USI's president and chief executive officer, said the acquisition complements the company's existing operations in Missouri and the central U.S., where it also owns Capital Electric Construction Co. Inc., Kansas City, Mo., and Capital Electric Line Builder Inc., Leavenworth, Kan. It acquired these companies earlier this year.

The acquisition of Oregon Electric Construction gives USI/MDU Resources another electrical contracting firm with expertise in power-line construction. The 50-year-old contractor specializes in new construction, repair, maintenance and service work for high-tech, industrial, health care, commercial, institutional and power generation customers. The company also provides preconstruction, design-build, design-assist and turnkey services for electrical and integrated systems work.

Oregon Electric and Bell Electrical management teams will both continue to manage the operations.