The president of Montana-Dakota Utilities Co. announced his plans for retirement Thursday.

Bruce T. Imsdahl, president and chief executive officer of the utility company, plans to retire on June 5; Imsdahl also served as president and chief executive officer of Great Plains Natural Gas Co., and chief executive officer of Cascade Natural Gas Co.

Imsdahl became president of Montana-Dakota and Great Plains in 2003, and became chief executive officer of both in November 2004. He was named CEOof Cascade after MDUResources acquired that company in 2007.

He began his acreer with Montana-Dakota Utilities in 1970 as a staff engineer, then advanced through several positions before becoming vice president of power supply in 1989. Two years later, he became vice president of energy supply.

"Bruce is widely respected within the industry, as well as by employees,"said Terry Hildestad, president and CEOof MDUResources Group Inc. "He leaves the company in a strong financial position and well-prepared for continued success.

- Crystal R. Reid