General Motors Co. Chief Executive Officer Dan Akerson

General Motors Co. Chief Executive Officer Dan Akerson

Daniel Acker/Bloomberg

General Motors Co. Chief Executive Officer Dan Akerson would no longer protect his marketing head after a whistle-blower stepped forward and the Detroit-based company determined Ewanick was spreading the price of the agreement with English soccer team Manchester United among several different marketing budgets to avoid his boss’s spending limits, people familiar with the situation said.