Elizabeth Vargas and Bob Woodruff on Monday were officially named co-anchors of ABC News’ “World News Tonight.” The pairing, reported Oct. 3 in TVWeek, will debut Jan. 3.

ABC News said it is expanding “World News Tonight” with a live West Coast version of the newscast. Three feeds will be anchored live by Ms. Vargas and Mr. Woodruff: at 6:30 (ET), 8:30 and 9:30. The network also plans to make versions of its reports available over the Internet during the afternoon and evening.

Ms. Vargas will remain co-anchor of ABC News’ “20/20.” She has been a regular substitute anchor on “World News Tonight” for several years, and has anchored the evening newscast once a week since April. She was also anchor of “World News Tonight Sunday.”

Ms. Vargas is the first woman to anchor a network newscast since Connie Chung was paired with Dan Rather on CBS in 1995.

Mr. Woodruff has been anchor of the weekend editions of “World News Tonight” and a regular substitute anchor for the weekday broadcast.