One day after Fox News Channel ended contract talks with senior correspondent and weekend show host Rita Cosby, MSNBC announced it is hiring Ms. Cosby as a special correspondent and anchor for whom a weeknight show will be developed for fourth-quarter launch.

Contrary to last week’s rumors that Ms. Cosby would get the 10 o’clock hour hosted by Joe Scarborough, sources familiar with the situation said flatly that MSNBC has no plans to replace Mr. Scarborough.

Ms. Cosby became one of the founding correspondents for Fox News Channel in 1995 after having been a reporter for CBS-affiliated WBTV in Charlotte, N.C. In her decade with Fox, the Emmy winner landed many newsmaker interviews and sometimes raised eyebrows when she became part of the story, such as when Oklahoma City bomber Timothy McVeigh wrote her a letter explaining his motives.

“Rita is a tireless and talented journalist and we are thrilled to welcome her to MSNBC,” said MSNBC President Rick Kaplan in the announcement Friday. “She continually manages to secure the most sought-after interviews and handles them brilliantly. Rita will play a prominent role at MSNBC as an anchor and special correspondent. We are looking forward to starting development of her new program.”

Meanwhile, Fox News is expected to use substitute hosts for “The Big Weekend Story,” which is telecast four times each weekend and which Ms. Cosby last hosted May 7.