MDUResources Group Inc. announced record second-quarter earnings of $89.3 million, including record growth in construction services, natural gas and oil production and construction materials and mining business.

MDU Resources Group Inc., is the parent company of Montana-Dakota Utilities and other natural resources, mining and construction companies. Its second quarter earnings of $89.3 million, or 49 cents per share, compared with $71.3 million, or 39 cents a share, in the second quarter of 2006.

Profit guidance increased to a range of $2.15 to $2.35, taking into account the estimated third-quarter growth of $90 million on the sale of domestic independent power production assets and earnings from discontinued operations.

Without the estimates from the asset sale, guidance for 2007 had been increased to a range of $1.65 to $1.85.

The construction service business increased earnings by 35 percent due to increased margins and revenues, according to the news release. Higher natural gas prices and a 4 percent production increase grew earnings in MDU's natural gas and oil production segment by 14 percent, and electric and natural gas distribution earnings grew due to higher retail sales and energy-related services margins.

MDUalso recently completed the acquisition of Cascade Natural Gas Corp., valued at $475 million and doubling the number of natural gas customers.