Barra also pledged on the company's website to employees that senior leadership would be held accountable for dealing with any safety concerns raised by a new program announced last week to encourage workers to voice concerns openly or anonymously.

"Importantly, we also promise accountability from our senior leadership back to these employees that we will take action or close each issue in a timely fashion," Barra wrote yesterday.

Selim Bingol, who late in 2012 added public policy to his public-relations duties, is leaving the company to pursue other interests, GM said. He joined the automaker in 2010, coming to the company from Fleishman-Hillard. Before that he had been at AT&T Inc., where he had worked under GM's then-CEO Ed Whitacre, who was succeeded at the automaker later that year by Dan Akerson. Bingol's replacement will be named later, GM said.