Diane Sawyer stepping down as 'World News' anchor

NEW YORK (KABC) -- Diane Sawyer will be leaving her role as "World News" anchor to take on a new role at ABC News, and David Muir will be replacing her, the network announced Wednesday.

Muir, 40, will take over starting Sept. 2. He first began reporting for "World News" with Peter Jennings, and he was a regular substitute for Sawyer on the program. Muir was the first American journalist to report from Mogadishu, Somalia, and his "Made in America" series earned an Emmy nomination.

"We have an extraordinary team of anchors who are gifted storytellers and uniquely skilled broadcasters," said James Goldston, ABC News president, in a statement. "For years to come, they will inspire us all to do our best work and set a high bar for excellence to inform, empower and inspire our viewers."

Sawyer anchored ABC News' flagship broadcast since December 2009 when Charlie Gibson retired. The network said 68-year-old Sawyer decided to step down "to concentrate full time on new programming," and she will "continue to interview the most extraordinary people in the world."

George Stephanopoulos will also take on a new role as ABC News chief anchor and will handle special reports and breaking news, the network said, adding that he will be leading election coverage in the fall and the 2016 presidential race.