In 1970, Koch joined Koch Industries under his brother Charles, to work as a technical-services manager. He founded the company's New York City office and in 1979 he became the president of his own division, Koch Engineering, renamed Chemical Technology Group. David's brothers Frederick and Bill had inherited stock in Koch Industries. In June 1983, after a bitter legal and boardroom battle, the stakes of Frederick and Bill were bought out for $1. 1 billion and Charles Koch and David Koch became majority owners in the company. Legal disputes against Charles and David lasted roughly two decades. Frederick and Bill sided with J. Howard Marshall III, J. Howard Marshall II's eldest son, against Charles and David at one point, in order to take over the company. In 2001, Bill reached a settlement in a lawsuit where he had charged the company was taking oil from federal and Indian land which ended all litigation between the brothers. CBS News reported that Koch Industries settled for $25 million. As of 2010, David Koch owned 42 percent of Koch Industries, as did his brother Charles. He held four U. S patents.