Oberhelman, 63, will leave the company at the end of March. He has been CEO since 2010 has been with Caterpillar Inc. for more than 41 years. Umpleby, who is 58 years old, is currently the president of Caterpillar's energy and transportation group. When he retires, Oberhelman will also step down from his position as chairman of the board and be replaced by board member Dave Calhoun as non-executive chairman. Calhoun is an executive of private equity firm The Blackstone Group LP. Caterpillar Inc., based in Peoria, Illinois, makes and sells construction and mining equipment.