NEW YORK --
Diane Sawyer says this week is her last as co-anchor of ABC's "Good Morning America" as she prepares to replace Charles Gibson on the network's "World News." Gibson is retiring. His last broadcast as anchor on "World News" will be Dec. 18. Sawyer starts Dec. 21.The 63-year-old Sawyer has been on "GMA" for 10 years. She says: "I've calculated -- 2,881 shows. Roughly."
Sawyer made the announcement Monday. She says she hopes "GMA" viewers will "celebrate with us this week, and laugh with us this week, and look back a little with us this week."