A group led by Minneapolis investor Irwin L. Jacobs said in a filing with the SEC that it increased its stake in the Omaha-based natural gas pipeline company to 9.1% from 7.9%. The Jacobs

group said the holdings were for investment purposes, although it might seek control of the company “under certain circumstances.” The group disclosed that it most recently purchased 525,450

shares at an average price of $47.90 a share. MORE TO READ