NBC News cut ties March 26 with former Republican National Committee chief Ronna McDaniel less than a week after hiring her as an on-air political contributor, a decision that followed a furious protest by some of its journalists and commentators.

In announcing the decision in a memo, NBC Universal News Group Chairman Cesar Conde apologized to staff members who felt let down by the hire, acknowledging he had signed off on it.

“No organization, particularly a newsroom, can succeed unless it is cohesive and aligned. Over the last few days, it has become clear that this appointment undermines that goal,” Mr. Conde said. But he said the network remained committed to centering “voices that represent different parts of the political spectrum.”