Navistar CEO steps down

US truck and bus maker Navistar International Corp. said Monday Chief Executive Officer Daniel Ustian is retiring, effective immediately. The company's statement did not mention the company's current troubles, which include a loss of $172 million in the second quarter and a U.S. Securities and Exchange Commission investigation of "certain accounting and disclosure matters," the Chicago Tribune reported. Company shares dropped 14 percent in value when the investigation became public the first week of August. The company's board appointed Lewis Campbell, former chairman, president and CEO of Textron Inc. to serve as interim CEO. Campbell is now on the board of directors at Bristol-Myers Squibb, Sensata Technologies Holding N.V. and Noblis Inc., a not-for-profit science, technology and strategy organization. After 37 years with Navistar, Ustian is also quitting the board of directors, the company said. The changes include a promotion for Troy Clarke, now president of truck and engine operations. He will be president and chief operating officer for the company.