A portion of Caterpillar's business is in the manufacturing of diesel and natural gas engines. In addition to their use in the company's own vehicles, are used as the marine vessels and ships, as well as providing the power source for peak-load power plants and emergency generators.
In June 2008, Caterpillar announced it would be exiting the on-highway diesel engine market in the United States before updated 2010, as costly changes to the engines (which only constituted a small percentage of Caterpillar's total engine sales) would be likely. In October 2010, Caterpillar announced it would buy German engine-manufacturer.
