The person, who asked not to be identified because the announcement had not been made, said Whitacre will say that he is taking the job for good, as well as give an update on GM's business plan.
Whitacre, 68, is a former CEO of telecommunications giant AT&T Inc.
He has been serving as interim CEO since the board ousted former CEO Fritz Henderson on Dec. 1. GM had hired a firm to conduct a global search for a successor.
Whitacre often says in a folksy Texas drawl that he knows little about cars. But he's already shaken up the company by hiring a new chief financial officer and transferring the old one to China, firing the Chevrolet and Buick-GMC brand managers, combining sales and marketing and consolidating control of GM's core North American market under one executive.
He also seems impatient to spur the plodding culture of GM, where decision by committee, an isolated upper management and fear of risk produced mediocre cars for years.
He wants to increase GM's sales and market share while shifting the company's focus from trucks to cars. And he aims to repay $8.1 billion in U.S. and Canadian government loans by the end of June.