Breaking: Six months into its run, “CBS This Morning” is making an anchor change.

CBS News Chief White House Correspondent Norah O’Donnell has been named co-host of “CBS This Morning” replacing Erica Hill who first came to CBS News in 2008, while still with CNN, to co-anchor the weekend “Early Show.” In January, 2010 she joined CBS fulltime.

O’Donnell will join co-hosts Charlie Rose and Gayle King beginning this fall. CBS says Hill’s future with CBS News is being discussed.

“CBS This Morning,” while still the #3 show in the morning, has been making ratings gains of late. Last week, the show was up +7% in total viewers and up +6% in younger viewers compared to the same week last year when “Early Show” was in production. O’Donnell filled-in on the show last week.

“This is a very exciting development for our morning program and for all of CBS News,” says CBS News Chairman Jeff Fager. “Norah is an accomplished reporter with all the skills for the job. She’s a hard worker who knows her story and, as she has shown time after time at the White House, she can think on her feet on live television.”

O’Donnell joined CBS News a year ago, after spending 11 years at NBC News and MSNBC. She will continue as Bob Schieffer‘s substitute on “Face the Nation.”