Charlie Gibson has stepped down as ABC’s World News anchor and Diane Sawyer has been named as his successor.

Sawyer has been the longtime co-host of ABC’s Good Morning America.

Richard Wald, a former news executive at ABC and NBC told The New York Times:

“You’re going to have, for the first time ever, two women competing as solo anchors in a television framework that just — within living memory — sort of destroyed every woman who tried to do it.”

Gibson’s decision to leave ABC was sudden and there is no plan yet for replacing Sawyer on Good Morning America.

A “veteran television news industry executive” who asked the Times for anonymity “to speak candidly about the competition” said:

“We’ll find out whether people don’t want to watch a woman anchor the news or whether they just didn’t want to watch Katie [Couric, CBS anchor].”

Of the three major U.S. networks, Couric’s broadcast on CBS is consistently third in ratings.

The changes will be effective in January.