08/27/2014 01:49 pm ET

Diane Sawyer Gets Ready To Bid Farewell To 'World News'

Ida Mae Astute via Getty Images

Wednesday night will be Diane Sawyer's last night as anchor of ABC's "World News," the veteran journalist announced on Twitter.

The ABC News veteran revealed in June that she would be stepping down from her anchor post. She will be replaced by current weekend anchor David Muir, while George Stephanopoulos will cover breaking news stories for the network as "chief anchor."

CNN's Brian Stelter said Wednesday that ABC News' Amy Robach will fill in for Sawyer on Thursday and Friday this week, before David Muir officially assumes the position next week.

Sawyer has been at the helm of "World News" since 2009 when she took over for Charlie Gibson. She said in a statement that she will use her time now to focus on primetime specials and to make appearances on other ABC News programs.

"World News" also confirmed that Wednesday will be her final appearance: