Diane Sawyer Steps Down From 'World News,' And ABC Tears Up The Network News Script

THE VIEW - (11.6.12) Guests include Diane Sawyer (ABC's 'World News Tonight') and the cast of 'Jersey Shore' today on 'The Vi
THE VIEW - (11.6.12) Guests include Diane Sawyer (ABC's 'World News Tonight') and the cast of 'Jersey Shore' today on 'The View.' 'The View' airs Monday-Friday (11:00 am-12:00 pm, ET) on the ABC Television Network. (Photo by Lou Rocco/ABC via Getty Images) DIANE SAWYER

Diane Sawyer is stepping down as the anchor of ABC's "World News," the network announced on Wednesday. She will be replaced by David Muir, the program's weekend anchor, in September. However, the person ABC will turn to when major news breaks will not be Muir, but George Stephanopoulos, who was named the network's "chief anchor."

Sawyer has been the anchor of the network's flagship program since late 2009. Muir has been weekend anchor since 2011. He is also co-anchor of "20/20."

Sawyer will now "concentrate full time on new programming," producing specials and doing interviews, ABC said. Her departure means that, once again, all three main evening news broadcasts will be anchored by white men.

ABC News president James Goldston told staffers in a note that Sawyer had been having discussions about a new role for herself since "the end of last year," and vowed she would stay with the network "for many years to come."

In a statement, Sawyer said, “I can’t wait to continue bringing more of my specials to prime time and appearing on all ABC News broadcasts, as well. And to my friends and colleagues George and David – congratulations. I look forward to exciting work together and great times ahead."

In some ways, though, Stephanopoulos's new assignment was the most intriguing. He will anchor breaking news and be the leading face of ABC's election coverage starting with this year's midterms in November. Those roles typically go to the anchor of the evening news, but Stephanopoulos is staying at "Good Morning America" and "This Week." The two men had long been seen as vying to succeed Sawyer, and the network appears to have resolved that issue by splitting up her role between them. Moreover, ABC was unlikely to want to rock the boat at either "GMA" or "This Week," both of which have been seeing their best ratings in decades.

The announcement about Stephanopoulos's enhanced presence across the network was seen by many as a major rewiring of the traditional nightly news anchor role, and a symbol of the new dominance of morning shows throughout the TV news business.

Muir's biggest task will be to finally beat "NBC Nightly News" in the ratings.

Under Sawyer's tenure, "World News" came within striking distance of "Nightly News"; in recent months, Sawyer has often beaten NBC's Brian Williams in the key A25-54 demo. Williams has remained in first place overall, however. ABC is hoping Muir can slay the last NBC dragon; the network has already pulled past both "Today" and "Meet The Press."

ABC also repeatedly combated charges that Sawyer had steered the newscast in a softer direction during her years in the anchor chair. In his note, Goldston emphasized what he called the "important, brilliant and impactful reporting" that he said "World News" had produced.