MDU Resources Group Incorporated. The Group's principal activities are to generate, transmit and distribute electricity. The Group operates in seven segments. Electric segment generates, transmits and distributes electricity. Natural gas distribution segment distributes natural gas. Utility services segment provides engineering, design and build capabilities. Pipeline and energy segment includes natural gas transportation, underground storage and gathering services. Natural gas and oil production conducts acquisition, exploration and production activities. Construction materials and mining markets crushed stone, sand, gravel and other materials. In Independent power production segment, electricity produced is sold under long-term contracts to nonaffiliated entities. Construction materials and mining accounted for 48% of 2002 revenues; Utility services, 23%; Natural gas distribution, 10%; Electric, 8%; Oil and gas production, 6%; Pipeline and energy services, 5%; Independent power production, nom.