On 29 October 2010, Koch was announced as designated chief executive officer of Bilfinger Berger, Germany's second-largest builder. In the following years, he orchestrated a reshuffle at the company away from civil engineering and construction in favor of higher-margin industrial services. During his tenure, Bilfinger Berger also agreed with the United States Department of Justice in 2013 to pay $32 million to resolve U.S. criminal charges that it bribed Nigerian officials to obtain contracts on a gas project in the African nation. In August 2014, he stepped down from the position on mutually agreed terms after he took responsibility for two profit warnings.